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PhD subjects

67 sujets IRAMIS

Dernière mise à jour : 20-04-2021


• Accelerators physics

• Analytic chemistry

• Artificial intelligence & Data intelligence

• Chemistry

• Environment and pollution

• Materials and applications

• Mesoscopic physics

• Molecular biophysics

• New computing paradigms, circuits and technologies, incl. quantum

• Physical chemistry and electrochemistry

• Plasma physics and laser-matter interactions

• Radiation-matter interactions

• Radiobiology

• Soft matter and complex fluids

• Solid state physics, surfaces and interfaces

• Structural biology

• Ultra-divided matter, Physical sciences for materials

 

Demonstrator of chromogenic materials for multi-target detection: study of chemical reactivity and diffusion

SL-DRF-21-0458

Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Edifices Nanométriques

Saclay

Contact :

Laurent MUGHERLI

Martine Mayne

Starting date :

Contact :

Laurent MUGHERLI
CEA - Liste des pôles/Liste des départements/Liste des services/LEDNA

0169089427

Thesis supervisor :

Martine Mayne
CEA - DRF/IRAMIS/NIMBE/LEDNA

01 69 08 48 47

Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=lmugherl

Laboratory link : http://iramis.cea.fr/nimbe/ledna/

No multi-gaz sensor comes with the required levels of sensitivity, selectivity, fast response and simplicity. Colorimetric detectors based on the use of porous materials are well suited to meet this challenge, particularly in association with microfluidic processes. In parallel with ongoing projects calls integrating complex microfluidic approaches, this thesis aims at understanding the links between reactivity, porosity and physico-chemistry of materials, diffusion of gases from the environment to the probes. Based on the acquired expertise a simplified demonstrator will be produced.
Formic Acid as a C1 platform chemical

SL-DRF-21-0439

Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire de Chimie Moléculaire et de Catalyse pour l’Energie

Saclay

Contact :

Emmanuel NICOLAS

Thibault CANTAT

Starting date : 01-10-2021

Contact :

Emmanuel NICOLAS
CEA - DRF/IRAMIS/NIMBE/LCMCE

01 69 08 26 38

Thesis supervisor :

Thibault CANTAT
CEA - DRF/IRAMIS/NIMBE/LCMCE

01 69 08 43 38

Personal web page : http://iramis.cea.fr/nimbe/Phocea/Membres/Annuaire/index.php?uid=enicolas

Laboratory link : http://iramis.cea.fr/nimbe/lcmce/

Formic acid is a molecule that is easily obtained through CO2 electroreduction. Its intrinsic reactivity would allow to use it as a renewable source of both carbon and hydrogen. Nevertheless, the hydrogen atoms on formic acid present two antagonist characters: one is hydridic while the other is acidic; the major reaction that can occur is thus its dehydrogenation back to CO2 and H2.



We envision in this PhD thesis to conceive and synthesize new organometallic catalysts that will allow taming the reactivity of formic acid, especially avoiding the dehydrogenation, to use it as a carbon and hydrogen source in other reactions. On one hand, its disproportionation (consisting in redistributing the hydrides from three formic acid molecules on a single carbon atom) to methanol, an energetically relevant molecule that can be used as a liquid fuel. On the other hand, reactions of alkene hydrocarboxylations, that will allow the synthesis of carboxylic acids from renewable compounds.
Boundary layers and dissipation measurements in free-surface and turbulent flows

SL-DRF-21-0428

Location :

Service de Physique de l’Etat Condensé

Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes

Saclay

Contact :

Sébastien AUMAITRE

Starting date : 01-09-2021

Contact :

Sébastien AUMAITRE
CEA - DRF/IRAMIS/SPEC/SPHYNX


Thesis supervisor :

Sébastien AUMAITRE
CEA - DRF/IRAMIS/SPEC/SPHYNX


Personal web page : http://iramis.cea.fr/Pisp/sebastien.aumaitre/

Laboratory link : http://iramis.cea.fr/spec/sphynx/

Turbulence occurs almost everywhere form atmospheric motion to vehicle displacement and industrial fluid transport and it still an intense subject of fundamental research. Indeed, because they are highly nonlinear, the turbulent flows are no fully predictable theoretically. Moreover, those nonlinearities generate many length and time scales and direct numerical simulations cannot access to the complexity of the flow during longtime. In most cases, numerical studies of turbulent flows require a certain level of modeling with ad-hoc parametrizations. This is why experiments remain a cornerstone element to study turbulence.



Among key quantities that deserve intensive study in turbulent flows are the velocity gradients because they are involved in dissipative processes, shear stress and boundary layers. They are at play in various phenomena: the flow structure interactions, the energy transfer in fluids, and exchange through atmosphere and ocean interfaces… . This led us to develop a new measurement technique to probe the norm of the velocity gradients in fluid flows. This optical method is based on the Diffusing Wave Spectroscopy (DWS). Depending on the optical arrangement, we can measure the velocity gradients near a surface locally or we can get spatially resolved map of them. A global estimation of the entire dissipation is also possible.



Up to now, we qualified this technique on well-known flows. The aim of this PhD thesis is to apply the DWS on flows where it will be able to resolve physical issues. Among them is the free surface flow with gravito-capillary surface waves. The properties of the boundary layer associated with the wavy surface is still puzzling especially in the limit of vanishing viscosity. This boundary layer plays a big role in the modeling of the interactions between surface waves and underneath streams. It must have strong impact on the atmosphere-ocean energy exchange, which is a key point of the climate modelling. Experimentally, it is a challenging to estimate the velocity gradients just below a moving interface. DWS has the potential to probe this boundary layer in a non-intrusive fashion in laboratory experiment. This technique also opens an experimental avenue to characterize the crucial impact of surface contamination on interfacial momentum transfer at the wavy surface. Another promising development path is to apply the DWS to fully turbulent flows. For instance, in order to get a better understanding of the energy cascade form large injection scale to small dissipative one, we would like to check the dissipation response to a perturbation of the energy injection. DWS will ultimately provide a unique opportunity for time-resolved experimental measurements of the turbulent dissipation rate, leading to a quantitative characterization of the temporal dynamics of the turbulent energy cascade.



We are looking for student with a strong appeal and skill on various aspects of experimental physics (hydrodynamics, optics and data processing). Nevertheless, the interpretation of experimental data will require also theoretical and numerical modeling. The PhD thesis will take place at the SPEC, a laboratory of the CEA-Saclay. Basile Gallet and Sébastien Aumaitre will supervise this thesis. They both develop research activities on nonlinear physics mainly applied to geophysics fluid dynamics and turbulence. For a part of them, Basile Gallet received the support of the European research Council (ERC flave).

Carbon nanotube optoelectronic devices for silicon photonics

SL-DRF-21-0438

Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Innovation, Chimie des Surfaces Et Nanosciences

Saclay

Contact :

Arianna FILORAMO

Starting date : 01-09-2020

Contact :

Arianna FILORAMO
CEA - DRF/IRAMIS/NIMBE/LICSEN

01-69-08-86-35

Thesis supervisor :

Arianna FILORAMO
CEA - DRF/IRAMIS/NIMBE/LICSEN

01-69-08-86-35

Personal web page : http://iramis.cea.fr/nimbe/Phocea/Membres/Annuaire/index.php?uid=filoramo

Laboratory link : http://iramis.cea.fr/nimbe/licsen/

Thanks to their outstanding electrical, mechanical and chemical characteristics, carbon nanotubes have been demonstrated to be very promising building blocks for future nanoelectronic technologies. In addition, recently their optical properties have attracted more attention because of their typical fundamental optical transition in the NIR [1-2] in a frequency range of interest for the telecommunications. The idea is to combine their particular optical features, inferred by their one-dimensional character, with their assessed exceptional transport and mechanics characteristics for hybrid optoelectronics/optomechanics application [3-5].



Recently, integrated hybridization approaches of photonics nanostructures hosting various kind of materials have raised great interest. Indeed, silicon is the base of current information processing technology while being an indirect bandgap material with poor electro-optic properties. Integrating SWNT onto Si photonic platform will enable to exploit their optical properties with the capability to electrically drive them. However, before that this can be effectively realized some fundamental studies are necessary.



Here, we will consider the mechanism involved in the electroluminescence and photoconductivity: both the carrier injection and the mechanisms leading to radiative recombination are to be considered. We will perform studies onto semiconducting nanotubes that we will extract from the pristine mixture by a method based on selective polymer wrapping [6-14]. Specifically we will reduce the distribution in chiralitiy to be able to study the characteristic of excitonic trapped states. Indeed, the comprehension of these phenomena is extremely important to obtain performant devices at room temperature (photodetectors, LED and single photon sources). Finally, non-linear optical properties will be considered to integrate new functionalities in silicon photonics platform [15-18].





[1] S. M. Bachilo et al. Science 298, 2361 (2002) ;

[2] O’Connell M. J. et al., Science 297, 593 (2002) ;

[3] Freitag et al., NanoLetter 6, 1425 (2006) ;

[4] Mueller et al., NatureNanotech. 5, 27 (2010) ;

[5] S.Wang et al. Nano Letter 11, 23 (2011);

[6] Nish, A. et al. Nat. Nanotechnol. 2, 640 (2007) ;

[7] Chen, F. et al. Nano Lett. 7, 3013 (2007) ;

[8] Nish, A. et al. Nanotechnology 19, 095603 (2008) ;

[9] Hwang, J.-Y. et al., J. Am. Chem. Soc. 130, 3543-3553 (2008) ;

[10] Gaufrès E. et al., Appl. Phys. Lett. 96, 231105 (2010) ;

[11] Gao, J. et al. Carbon 49, 333 (2011);

[12] Tange M. et al. ACS Appl. Mater. Interfaces 4, 6458 (2012)

[13] Sarti F. et al Nano Research 9, 2478 (2016)

[14] Balestrieri M. et al Advanced Functional Materials 1702341 (2017).

[15] Margulis Vl.A. et al. Physica B 245, 173 (1998)

[16] Arestegui O.S. Optical Materials 66, 281 (2017)

[17] Chu H. et al. Nanophotonics 9(4): 761 (2020),

[18] Song B. et al. ACS Photonics 7, 2896 (2020)

Electron minigun for gaz conversion

SL-DRF-21-0443

Research field : Accelerators physics
Location :

Service Laboratoire Interactions, Dynamique et Lasers

Saclay

Contact :

Marie GELEOC

Jean-Philippe RENAULT

Starting date : 01-09-2021

Contact :

Marie GELEOC
CEA - DRF/IRAMIS/LIDyL/SBM


Thesis supervisor :

Jean-Philippe RENAULT
CEA - DRF/IRAMIS/NIMBE/LIONS

01 69 08 15 50

Personal web page : http://iramis.cea.fr/Pisp/marie.geleoc/

Laboratory link : http://iramis.cea.fr/lidyl/sbm/

This subject is part of the fight against air pollution and global warming. Electron beam-based techniques for the treatment of gaseous effluents (EBFGT) are routinely implemented with energies from 300 keV to 1 MeV, in the absence of existing tools lighter than accelerators to produce them. The aim here is to develop a flexible mini electron source with a more relevant energy, then optimize it for a more energy-efficient conversion of CO2 or N2, based on the skills in miniaturized source and gas radiolysis developed at IRAMIS.
Design of an automatic module using fluidics and NMR micro-detection for real-time monitoring of chemical reactions

SL-DRF-21-0485

Research field : Analytic chemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Structure et Dynamique par Résonance Magnétique (LCF)

Saclay

Contact :

Patrick BERTHAULT

Starting date : 01-01-2021

Contact :

Patrick BERTHAULT
CEA - DRF/IRAMIS/NIMBE/LSDRM

+33 1 69 08 42 45

Thesis supervisor :

Patrick BERTHAULT
CEA - DRF/IRAMIS/NIMBE/LSDRM

+33 1 69 08 42 45

Personal web page : http://iramis.cea.fr/Pisp/patrick.berthault/

Laboratory link : http://iramis.cea.fr/nimbe/lsdrm/

More : http://www.cortecnet.com

A large number of chemical processes are complex and require for their optimization to understand the reaction mechanisms by real-time observation of intermediate compounds and end products. Nuclear Magnetic Resonance (NMR) can perform this task, but this requires taking into account several aspects: to overcome the lack of intrinsic sensitivity of NMR, to bring the detection zone as close as possible to the synthesis reactor and to be able to accurately quantify the data obtained.



Recently LSDRM researchers developped and patented a 3D-printed NMR device based on a mini bubble pump associated with fluidics and micro-detection, installable on a commercial probe inside the NMR magnet. An insert version plugged into a micro-imaging probe and a version using an inductive coupling between the micro-coil and the commercial coil have been developed. The system allows a significant improvement of the NMR signal for the slowly relaxing nuclei, since the constituents of the reaction mixture are located in a magnetic field close to that of the NMR study, thus allowing a pre-polarization of the whole solution. Moreover, thanks to the controlled of the flow, between two scans, the fresh spins replace those previously excited in the detection region; it is therefore not necessary to wait several relaxation times between each scan acquisition.



Based on CortecNet’s expertise in the synthesis of stable isotope-enriched compounds, and LSDRM, a research laboratory recognized for its know-how in the creation of innovative devices for improving the NMR technique, the objective of this research project is to develop a complete NMR monitoring system, in situ, of chemical syntheses in order to provide organic chemists with an indispensable measuring instrument in their daily activities.
Advanced machine learning for Ion Beam Analysis

SL-DRF-21-0448

Research field : Artificial intelligence & Data intelligence
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire d’étude des éléments légers

Saclay

Contact :

Hicham KHODJA

Starting date : 01-10-2021

Contact :

Hicham KHODJA
CEA - DRF/IRAMIS/NIMBE/LEEL

01 69 08 28 95

Thesis supervisor :

Hicham KHODJA
CEA - DRF/IRAMIS/NIMBE/LEEL

01 69 08 28 95

Personal web page : http://iramis.cea.fr/Pisp/hicham.khodja/

Laboratory link : http://iramis.cea.fr/NIMBE/LEEL/

Ion Beam Analysis spectroscopies make possible to obtain complete quantitative chemical maps (including certain isotopes of light elements) of samples, generally without having to require references. These techniques can be depth resolved, and when performed using a microbeam, one can access quantitative 3-dimensional chemical imaging. The fields of application are varied, with a predominance of materials sciences, sometimes in operando mode.



The processing of these data is based today on the adjustment of the spectra produced by the simulation, each technique calling on distinct fields of physics. This processing is time consuming, and one can face situations where input data of the simulations is missing.



Another approach based on machine learning from simulated data is possible, but the first explorations reported in the literature were limited to simple, monotechnical situations. Today, new learning architectures are available and allow to foresee a significant improvements in computation times compared to those of adjustment tools for experimental spectra, this by establishing robust predictive models.



The proposed thesis will consist in studying and determining the most suitable learning architecture, in particular for the discrimination and taking into account of low intensity signals, and in enriching the spectra dictionaries and fundamental databases necessary for the simulation using generative models.
Catalytic cleavage of C – O and C – N bonds applied to the reductive depolymerization of plastic wastes

SL-DRF-21-0442

Research field : Chemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire de Chimie Moléculaire et de Catalyse pour l’Energie

Saclay

Contact :

Thibault CANTAT

Jean-Claude Berthet

Starting date : 01-10-2021

Contact :

Thibault CANTAT
CEA - DRF/IRAMIS/NIMBE/LCMCE

01 69 08 43 38

Thesis supervisor :

Jean-Claude Berthet
CEA - DRF/IRAMIS/NIMBE/LCMCE

01 69 08 60 42

Personal web page : http://iramis.cea.fr/Pisp/jean-claude.berthet/

Laboratory link : http://iramis.cea.fr/Pisp/thibault.cantat/index.html

At the end of their life, plastics are still too valuable to be landfilled. As part of the new European directives and French law on the circular economy, the carbonaceous matter should be reused. Mechanical recycling is thus expanding but still of limited scope. A recent and promising approach aims to chemically treat certain plastics to recover their carbon content by regenerating in particular the base monomers which can be used again indefinitely or recover chemical molecules with high added values. Currently in its infancy, this path requires the development of efficient processes making it possible to treat each of kind of plastic materials (carbonaceous, oxygenated, nitrogenous such as polyethers, polyesters and polyamides, etc.). The depolymerization of these materials to enter in a circular economy and to selectively produce convenient molecules thus remains a challenge.



The Laboratory of Molecular Chemistry and Catalysis for Energy (UMR CEA / CNRS 3299) has developed an original strategy for the reductive depolymerization of a variety of oxygenated plastics such as polyethers, polyesters and polycarbonates, towards derived monomers and hydrocarbons. The catalysts used are iridium or boron complexes, which are costly, in combination with hydrosilane reducing agents (R3SiH) and then cheap anions in the presence of silanes. These works led to two patents.



This doctoral project aims to use new, less expensive and selective molecular metal complexes to depolymerize oxygenated and nitrogenous plastics (such as polyamides for example), under mild conditions, in combination with hydrosilanes, boranes or even silicon formates species as reducing agents.
Molecular catalysts for the selective reduction of nitrates

SL-DRF-21-0449

Research field : Chemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire de Chimie Moléculaire et de Catalyse pour l’Energie

Saclay

Contact :

Lucile ANTHORE

Thibault CANTAT

Starting date : 01-10-2021

Contact :

Lucile ANTHORE
CEA - DRF/IRAMIS/NIMBE/LCMCE

01 69 08 91 59

Thesis supervisor :

Thibault CANTAT
CEA - DRF/IRAMIS/NIMBE/LCMCE

01 69 08 43 38

Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=lanthore

Laboratory link : http://iramis.cea.fr/nimbe/lcmce/

More : http://iramis.cea.fr/Pisp/thibault.cantat/

The main part of industrial nitrogen containing products stems from the reduction of atmospheric nitrogen N2 into ammonia NH3 via the Haber-Bosh process. Their degradation leads to an accumulation of nitrogen oxides in Nature, their reduction back to N2 being only performed by the natural denitrification process. This observation calls for the use of nitrogen oxides (nitrates, nitrites…) as building blocks for the synthesis of nitrogen derivatives in fine chemistry (pharmaceutical and agrochemical industries, for example). To do so, the first step will be to control and understand the selective reduction of N-O bonds.



This thesis thus aims at developing new homogeneous catalytic systems to selectively reduce nitrates NO3- in nitrites NO2- or hydroxylamine NH2OH using mild reducing agents such as organosilanes (R3SiH, R3SiSiR3) or organoboranes (R2BH, R2BBR2). All along this project, a strong focus will be made on the understanding of the mechanism, thanks to experimental mechanistic studies as well as computational studies (DFT calculations) to better understand the reduction of the N-O bond.

Bioactive polymer-grafted nanoparticles and surfaces to limit the microbe resistance

SL-DRF-21-0435

Research field : Chemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Innovation, Chimie des Surfaces Et Nanosciences

Saclay

Contact :

Geraldine CARROT

Starting date : 01-10-2021

Contact :

Geraldine CARROT
CEA - DRF/IRAMIS/NIMBE/LICSEN

01 69 08 41 47

Thesis supervisor :

Geraldine CARROT
CEA - DRF/IRAMIS/NIMBE/LICSEN

01 69 08 41 47

Personal web page : http://iramis.cea.fr/nimbe/Phocea/Membres/Annuaire/index.php?uid=carrot

Laboratory link : http://iramis.cea.fr/nimbe/licsen/

Recent studies have shown that after only a few hours of adhesion to the surface of receptor media, bacteria are able to "feel" contact with surfaces and to modify their proteome. Among the proteins over or under expressed, some are involved in the reactivity of bacteria to antimicrobials. We are working on surfaces modified with very effective bacteriostatic polymers. Through this project thesis, we would like to study more particularly the impact of these surfaces on the resistance of bacteria. For this purpose, 3D surfaces (particles) will be grafted in order to evaluate first the impact of interactions with bacteria directly in solution. Modified surfaces and nano-objects will be studied both in microbiology (bactericide effect, resistance of bacteria after contact, etc..), and via detailed physico-chemistry measurements (XPS, zetametry, scattering techniques, etc..) in order to understand the structure-properties relationship.

Porphyrin-based nanostructures

SL-DRF-21-0157

Research field : Chemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Innovation, Chimie des Surfaces Et Nanosciences

Saclay

Contact :

Stéphane CAMPIDELLI

Starting date : 01-10-2021

Contact :

Stéphane CAMPIDELLI
CEA - DRF/IRAMIS/NIMBE/LICSEN

01-69-08-51-34

Thesis supervisor :

Stéphane CAMPIDELLI
CEA - DRF/IRAMIS/NIMBE/LICSEN

01-69-08-51-34

Personal web page : http://iramis.cea.fr/Pisp/stephane.campidelli/

Laboratory link : http://iramis.cea.fr/nimbe/licsen/

The aim of this project is the synthesis of new molecular structures based on porphyrins for the formation of 0D, 1D and 2D nanostructures. Porphyrins are an important class of molecules that are essential to life through oxygen transport or photosynthesis. Beyond, their importance in Nature, porphyrin derivatives exhibit outstanding optical, electronic, chemical and electrochemical properties that make them promising candidates for applications in catalysis, electrocatalysis, optoelectronics and medicine.

In this project, the porphyrins will be studied in collaboration with several groups of Physicists in order to fabricate 1D or 2D covalent networks on surface via the "bottom-up" approach and to study their electronic and optical properties.
Synthesis and optical properties of graphene nanoparticles

SL-DRF-21-0156

Research field : Chemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Innovation, Chimie des Surfaces Et Nanosciences

Saclay

Contact :

Stéphane CAMPIDELLI

Starting date : 01-10-2021

Contact :

Stéphane CAMPIDELLI
CEA - DRF/IRAMIS/NIMBE/LICSEN

01-69-08-51-34

Thesis supervisor :

Stéphane CAMPIDELLI
CEA - DRF/IRAMIS/NIMBE/LICSEN

01-69-08-51-34

Personal web page : http://iramis.cea.fr/Pisp/stephane.campidelli/

Laboratory link : http://iramis.cea.fr/nimbe/licsen/

Graphene as a constituent of graphite was close to us for almost 500 years. However, it is only in 2005 that A. Geim and K. Novoselov (Nobel Prize in 2010) reported for the first time the obtaining of a nanostructure composed by a single layer of carbon atom. The exceptional electronic properties of graphene make it a very promising material for applications in electronic and renewable energies.



For many applications, one should be able to modify and control precisely the electronic properties of graphene. In this context, we propose to synthesize chemically graphene nanoparticles and study their absorption and photoluminescence properties. This project will be developed in collaboration with Physicists so the candidate will work in a multidisciplinary environment.
Biofilms on chip.

SL-DRF-21-0687

Research field : Environment and pollution
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Interdisciplinaire sur l’Organisation Nanométrique et Supramoléculaire

Saclay

Contact :

Yves BOULARD

Jean-Philippe RENAULT

Starting date :

Contact :

Yves BOULARD
CEA - DRF/JOLIOT/I2BC/

+33 169083584

Thesis supervisor :

Jean-Philippe RENAULT
CEA - DRF/IRAMIS/NIMBE/LIONS

01 69 08 15 50

Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=jrenault

Laboratory link : http://iramis.cea.fr/nimbe/lions/

Microplastics are an emerging pollution present in all environmental compartments (aquatic environments, atmosphere and soils). Their fate and life span in the environment depend closely on the microbial ecosystem (biofilm) that will form on their surface. However, these pollutions are highly mobile in the environment, which makes it difficult to understand the biodegradation mechanisms.



We therefore propose to follow this biodegradation on the long term by developing chips in a controlled environment.
Miniaturized fluidized beds for glycomic analysis

SL-DRF-21-0445

Research field : Materials and applications
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Interdisciplinaire sur l’Organisation Nanométrique et Supramoléculaire

Saclay

Contact :

Florent Malloggi

Patrick GUENOUN

Starting date : 01-09-2021

Contact :

Florent Malloggi
CEA - DSM/IRAMIS/NIMBE/LIONS

+3316908 6328

Thesis supervisor :

Patrick GUENOUN
CEA - DRF/IRAMIS/NIMBE/LIONS

01-69-08-74-33

Personal web page : http://iramis.cea.fr/nimbe/Pisp/florent.malloggi/

Laboratory link : http://iramis.cea.fr/nimbe/lions/

More : https://joliot.cea.fr/drf/joliot/Pages/Entites_de_recherche/medicaments_technologies_sante/SPI/LEMM.aspx

Glycomic analysis consist of extracting oligosaccharide (OS) profiles from all glycoproteins contained within a biological fluid of interest. Successful OS profiling relies on an efficient analytical technique, mass spectrometry (MS) in our approach, and sample preparation prior to analysis, starting with PNGase F enzymatic cleavage. Glycomic analysis general use in hospitals will be possible only if new techniques enhance and speed up sample preparation. This PhD aims at building fluidized bed within microsystems to perform PNGase catalysis.



Macroscopic fluidized beds consist of beads packed in a container with a porous membrane at the bottom through which a fluid can be homogeneously injected. Such devices are widely used for liquid-solid exchange processes because of their high surface to volume ratio. Downsizing this concept in microfluidics is a hot topic particularly for biotechnology applications where limited/expensive sample volume is often a strong constrain.



In this context, we plan to integrate micro/nanometric functionalized particles of fluidized bed within microfluidic channels, by using mini-membranes that will allow fluid circulation while blocking solid particles. Downsized equivalents to macroscopic membranes will be obtained either by soft-lithography restrictions, which should be readily implemented, or by a more innovative integration of porous silica, for which the effects of sol-gel reactions parameters on membranes properties (pores size, homogeneity, thickness, surface chemistry) will be explored.



In both cases, the generation of fluidized beds by injection of micro/nanometric functionalized particles (polymer and inorganic micro/nanoparticles) will be investigated as well as their use following reference protocols of PNGase enzyme cleavage as performed in typical glycomic analysis experiments.



Once this micrometric fluidized bed technology is demonstrated, it shall be easily transferred to other microsystems for various applications in biology or chemistry.

SL-DRF-21-0233

Research field : Materials and applications
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Innovation, Chimie des Surfaces Et Nanosciences

Saclay

Contact :

Pascal Viel

Starting date : 01-09-2021

Contact :

Pascal Viel
CEA - DSM/IRAMIS/NIMBE/LICSEN

01 69 08 41 47

Thesis supervisor :

Pascal Viel
CEA - DSM/IRAMIS/NIMBE/LICSEN

01 69 08 41 47

Personal web page : http://iramis.cea.fr/Pisp/135/pascal.viel.html

Laboratory link : http://iramis.cea.fr/nimbe/licsen/

Measurement of accidental radiation exposure by radio-induced defects in smartphones screens

SL-DRF-21-0456

Research field : Materials and applications
Location :

Laboratoire des Solides Irradiés

Laboratoire des Solides Irradiés

Saclay

Contact :

François Trompier

Nadege OLLIER

Starting date :

Contact :

François Trompier
IRSN -


Thesis supervisor :

Nadege OLLIER
CEA - DRF/IRAMIS/LSI

01 69 33 45 18

Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=ollier

Laboratory link : https://portail.polytechnique.edu/lsi/fr

In case of a large-scale radiological emergency, methods are needed to identify individuals in the

population who have been exposed and require immediate soins ?. There are no operational methods to date. The

glasses of smartphones’ touch screens keep in "memory" the trace of an irradiation with ionizing radiations by the

formation of so-called "radio-induced" defects. The measurement and quantification of these point defects, in

particular by electron paramagnetic resonance spectroscopy (EPR), makes it possible to estimate the dose deposited

in the glass and thus to estimate the exposure associated with the irradiation. However, an increased understanding of

the nature of the stable defects involved and their stability is necessary. Indeed, the nature of the point defects and

their properties are not known, moreover they are very dependent on the generation of Gorilla glass (Corning).

The aim of this thesis is to propose approaches or methods to quantify some of the defects that may be related to the dose delivered. Defects that are not induced by UV will be preferred.
Proton beam damage mechanisms in metal targets used for neutron production.

SL-DRF-21-0043

Research field : Materials and applications
Location :

Laboratoire Léon Brillouin

Groupe de Diffusion Neutron Petits Angles

Saclay

Contact :

Frédéric OTT

David SIMEONE

Starting date : 01-10-2021

Contact :

Frédéric OTT
CEA - DRF/IRAMIS/LLB/NFMQ

01 69 08 61 21

Thesis supervisor :

David SIMEONE
CEA - DES/DMN/SRMA

01-69-08-29-20

Personal web page : http://www-llb.cea.fr/Phocea/Pisp/index.php?nom=frederic.ott

Laboratory link : http://iramis.cea.fr/llb/Phocea/Vie_des_labos/Ast/ast_sstechnique.php?id_ast=2755

In recent years, different institutes have been considering the use of low energy accelerators (10 - 70MeV) for the production of neutrons and their use for neutron scattering. We can cite the SONATE project at CEA Saclay, HBS at F. Zentrum Jülich or ARGITU at ESS Bilbao. Neutron sources of this type would potentially have performance equivalent to that of a medium power research reactor for neutron scattering techniques. The different technological bricks (high current accelerator, advanced neutron moderator, instruments) exist. The last brick requiring validation is the target. On such installations, the target will be subjected to proton fluences on the order of 1E25 protons / m² during their lifetime. One of the problems encountered is the non-solubility of hydrogen in the metal which leads to the formation of blisters and damage in the material. We wish to experimentally study the behavior of different metals (Al and Ta) under very high irradiation fluences on the IPHI- Neutron facility. The modeling of the impact of irradiation on the modification of the limits of solubility, the change of phase (possible hydriding) as well as the ordering of the networks of hydrogen bubbles will be carried out within the framework of a phase field type approach.



This work is part of the CEA SONATE program on the development of new neutron sources using accelerators.
Electrodynamics of disordered superconductors, for the development of quantum phase slip junction devices

SL-DRF-21-0426

Research field : Mesoscopic physics
Location :

Service de Physique de l’Etat Condensé

Groupe Quantronique

Saclay

Contact :

Hélène Le SUEUR

Daniel ESTEVE

Starting date : 01-10-2021

Contact :

Hélène Le SUEUR
CNRS - SPEC

01 69 08 38 88

Thesis supervisor :

Daniel ESTEVE
CEA - DRF/IRAMIS/SPEC/GQ

0169085529

Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=hls

Laboratory link : http://iramis.cea.fr/spec/GQ

The Quantronics group at SPEC is performing research in fundamental solid state physics at very low temperature, and in particular in quantum electronics. One present goal of our team is to elucidate the last missing ingredient of mesoscopic superconductivity: the Quantum Phase Slip Junction.



A Quantum phase slip junction (QPSJ) consisting of very thin disordered superconducting wire is predicted to behave as a non-linear nondissipative capacitor, and to constitute an exact quantum dual of the well know and widely used Josephson junction. The availability of QPSJ would open a broad range of new possibilities for quantum circuit engineering.



By making nanowire resonators in order to realize QPSJ, we have evidenced a strong coupling of the resonator to surrounding charged Two Level Systems, an order of magnitude larger than what is expected from standard dipole / electric field coupling. We have shown this phenomenon is present in several superconductors who have in common their high inductance (high disorder). We have proposed recently [leSueur18] a new universal mechanism to explain this strong coupling, through mesoscopic fluctuations of the kinetic inductance. The general goal of the PhD detailed below is to fully characterize this mechanism.
Anti-bunched photons from Pauli exclusion principle

SL-DRF-21-0425

Research field : Mesoscopic physics
Location :

Service de Physique de l’Etat Condensé

Groupe Nano-Electronique

Saclay

Contact :

Carles ALTIMIRAS

Patrice ROCHE

Starting date : 01-10-2021

Contact :

Carles ALTIMIRAS
CEA - DRF/IRAMIS/SPEC/GNE

01 69 08 72 16

Thesis supervisor :

Patrice ROCHE
CEA - DRF/IRAMIS/SPEC/GNE

0169087216

Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=caltimir

Laboratory link : https://nanoelectronicsgroup.com/

Quantum transport investigates the dynamics of electrical circuits displaying a quantum mechanical behavior. This is achievable by patterning circuits in the nm/um scale in clean room environments, and cooling them at T~15 mK in dilution fridges. A remarkable aspect of such quantum dynamics is that the electrical current fluctuates, even in response to a strictly DC bias. Detecting these quantum fluctuations is highly informative as it conveys information on the granularity of charge, the statistics of the carriers but also on the characteristic transport times such as the electronic scattering time or on interaction effects. The electromagnetic field radiated by the quantum mechanical scattering of conduction electrons, might inherit their quantum properties as well.



In the last years, our lab has developed several experimental schemes and technics in order to measure efficiently such quantum fluctuations in the few GHz range. In a qualitative level, measuring at this frequency range fdet~6 GHz gives access to the quantum optical regime hfdet>>kBT, where one needs to provide a quantum description not only for the electrical current flowing through the conductor, but also for the electromagnetic fields exchanged with its detection scheme. This circuit quantum electrodynamics regime is appealing since the light-matter coupling, proportional to the detection impedance, can be engineered and take non-perturbative values unparalleled in other physical systems. Moreover using this frequency range increases the detection window and enables probing shorter transport time scales, or equivalently larger interaction energy scales.



The purpose of this PhD project is develop a new generation of radiofrequency impedance matching circuits, in order to increase notably the bandwidth of the detection window. The goal of this project is to obtain a detection bandwidth larger than the thermal bandwidth at 15 mK thus dfdet~1 GHz, with a detection impedance of the order to the resistance quantum RQ=h/e^2~25.8 kohm. Such a device would to enable us to detect how the sub-Poissonian properties of Fermions being scattered upon a potential barrier might imprint on the properties of the resulting radiated RF field [1, 2]. In practice, we will couple the coil to a quantum point contact developed on a 2D electron gas, giving rise to a single channel potential barrier with a tunable electronic transmission. We will amplify the radiated RF field leaking from the resonator in a HBT geometry, and sample it at room temperature, in order to compute its second order correlation, techniques well mastered in our group [3].





[1] Beenaker & Schomerus, Phys.Rev.Lett. 93, 096801 (2004)

[2] Hassler & Otten, Phys. Rev. B 92, 195417 (2015)

[3] Rolland et al., Phys.Rev.Lett 122, 186804 (2019)
Interaction of the HFq protein with the bacterial membrane and functional consequences on RNA export

SL-DRF-21-0414

Research field : Molecular biophysics
Location :

Laboratoire Léon Brillouin

Groupe Biologie et Systèmes Désordonnés

Saclay

Contact :

Véronique ARLUISON

Starting date : 01-09-2021

Contact :

Véronique ARLUISON
Université de Paris - DRF/IRAMIS/LLB/GBSD

01 69 08 32 82

Thesis supervisor :

Véronique ARLUISON
Université de Paris - DRF/IRAMIS/LLB/GBSD

01 69 08 32 82

Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=varluiso

Laboratory link : http://iramis.cea.fr/LLB/MMB/

Hfq is a pleiotropic regulator that mediates several aspects of bacterial RNA metabolism. The protein notably regulates translation efficiency and RNA decay in Gram-negative bacteria, usually via its interaction with small regulatory RNA. Our previous results evidenced that Hfq C-terminal region forms an amyloid-like structure and that these fibrils interact with membranes. The immediate consequence of this interaction is a disruption of the membrane.



In order to go into the details of the mechanism of interaction, the present PhD work will use different biophysical approaches, including molecular and cellular microscopy, infrared, neutron scattering, circular dichroism and ssNMR spectroscopies. By using these methods, we already evidence that Hfq C-terminal region influences the membrane integrity, which results in the formation of holes that could have an effect on bacterial RNA export outside of the cell. We hypothesize that the reported effect of this RNA-metabolism master regulator could be of primary importance for bacterial communication and the goal of the PhD work will be to analyze this possible function.
SRCD as a tool for nucleic acids secondary structure and fold determination

SL-DRF-21-0412

Research field : Molecular biophysics
Location :

Laboratoire Léon Brillouin

Groupe Biologie et Systèmes Désordonnés

Saclay

Contact :

Véronique ARLUISON

Starting date : 01-09-2021

Contact :

Véronique ARLUISON
Université de Paris - DRF/IRAMIS/LLB/GBSD

01 69 08 32 82

Thesis supervisor :

Véronique ARLUISON
Université de Paris - DRF/IRAMIS/LLB/GBSD

01 69 08 32 82

Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=varluiso

Laboratory link : http://iramis.cea.fr/LLB/MMB/

Nucleic acids (NA) perform crucial role in cells. Similarly to proteins, they can fold into complex structures that usually result from the assembly of minimal structures (called secondary structure). Our previous analyses performed at SOLEIL showed that SRCD provides important information about the conformation of NA, including analysis of helical parameters and base stacking.



With this PhD project, we propose to build a database to browse various RNA and DNA minimal structures using SRCD. This "reference library" will be used to identify the folding of NA and to distinguish them into groups. This database will allow us to develop a new algorithm based on an evaluation of the eigenvalues, obtained by the analysis of representative SRCD spectra experimentally obtained. In turn, our database will also provides a reference for NA SRCD spectra that will allow to model NA structures at the quantum scale.
Single Electron Spin Detection for Hybrid Superconducting Quantum Computing

SL-DRF-21-0422

Research field : New computing paradigms, circuits and technologies, incl. quantum
Location :

Service de Physique de l’Etat Condensé

Groupe Quantronique

Saclay

Contact :

Emmanuel FLURIN

Denis VION

Starting date : 01-09-2021

Contact :

Emmanuel FLURIN
CEA - DRF/IRAMIS/SPEC/GQ

0622623862

Thesis supervisor :

Denis VION
CEA - DRF/IRAMIS/SPEC/GQ

2 5529

Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=eflurin

Laboratory link : http://iramis.cea.fr/spec/gq/

The thesis is part of a research project aiming at using impurities trapped in solids as quantum bits integrated as a very high fidelity memory in superconducting quantum processors.



The crystalline defects of silicon and diamond can be apprehended as naturally trapped ions in an inert crystalline environment close to vacuum. Due to their immobility and their isolation in the crystal lattice, the electronic and nuclear spins of these ions exhibit excellent coherence times, ranging from a few seconds for electrons [1] to a few hours for nuclei. These systems are thus excellent candidates for encoding quantum information. On the other hand, superconducting circuits constitute one of the most successful technological platforms for quantum computation. Quantum bits are encoded in artificial electromagnetic oscillators; they are easily controllable and integrable. However, their coherence time does not exceed a few hundreds of microseconds and their manufacture is not reproducible, this is one of the main barriers toward the development of processors of more than 100 qubits.



Our group, a pioneer of superconducting circuits, is engaged in a long-term research project which aims at interfacing circuits with the electronic and nuclear spin of a unique crystal defect and thus combines the robustness of natural elements with the integrability of artificial circuits. The internship is based on recent results [1,2,3,4] of our team. For the first time, we have demonstrated the detection of a small spin ensemble (100-1000 spins) with a microwave photon detector based on a superconducting qubit processor. Our new type of microwave detector [4] enabled us to reach unprecedented sensitivity surpassing the standard quantum limit and has paved the way toward the detection and control of individual spins for quantum computing integration.



The goal will be first to optimize the coupling between the circuit and a single spin trapped in the silicon lattice and second to successfully detect the unique microwave photon generated by the de-excitation of the electron spin. This single photon will be captured and detected based on a superconducting qubit of the transmon type, a key element of the superconducting quantum processor, thus laying the foundations for this new architecture.
Hong-Ou-Mandel interferometric experiment in graphene

SL-DRF-21-0373

Research field : New computing paradigms, circuits and technologies, incl. quantum
Location :

Service de Physique de l’Etat Condensé

Groupe Nano-Electronique

Saclay

Contact :

Preden Roulleau

Patrice ROCHE

Starting date : 01-10-2021

Contact :

Preden Roulleau
CEA - DRF/IRAMIS/SPEC/GNE

0169087311

Thesis supervisor :

Patrice ROCHE
CEA - DRF/IRAMIS/SPEC/GNE

0169087216

Personal web page : http://iramis.cea.fr/Pisp/preden.roulleau/

Laboratory link : http://iramis.cea.fr/spec/GNE/

More : https://nanoelectronicsgroup.com/

Historically, the Hong-Ou-Mandel interferometric experiment has been performed to get time-domain information on the photon wave packets: it was a direct way to measure the time width of single photon wave packets. The lack of quadratic detectors to perform time auto-correlation at so low input level led them to consider the second order coherence g_2 (tau)=|Psi(x)¦Psi(x-tau)|^2 by colliding the idler and signal photons generated by parametric down-conversion of a laser source on a beam splitter.



Indeed, the interference of the two indistinguishable particles makes the particle detection statistics dependent on their wavefunction overlap. After N0 experiments, the particle number fluctuation is Delta_N^2~(1±|Psi(x)¦Psi(x-v_F tau)|^2), where the plus sign holds for bosons, the minus sign holds for fermions, tau is the time delay between particles and v_F is their velocity. For non-overlapping states at large tau, the fluctuations of two particles independently partitioned is found. For zero delay (full overlap), the bosonic bunching doubles the noise whereas the fermionic exclusion makes it vanish. Hong–Ou–Mandel experiments are now standard in quantum optics. With the use of electronic beamsplitters in GaAs/AlGaAs, d.c. and a.c. voltage sources have shown anti-bunching [1,2].



Recently we have shown that it was possible to mimic these beam splitters in graphene and to obtain Mach Zehnder interferometers with record visibility of 80% [3]. Based on this, we propose an original Hong Ou Mandel geometry to probe for the first time the fermion statistics in graphene.



During this training period, the student will join a running experiment. In parallel theoretical calculations will be done together with numerical simulation of electron collision in graphene. This proposal is part of the ERC starting grant COHEGRAPH (2016).



[1] J. Dubois, T. Jullien, F. Portier, P. Roche, A. Cavanna, Y. Jin, W. Wegscheider, P. Roulleau, & D. C.Glattli , Nature 502, 659-663 (2013)

[2] E. Bocquillon et al., Science 339, 1054 (2013)

[3] Coherent manipulation of the valley in graphene, M. Jo, P. Brasseur, A. Assouline, W. Dumnernpanich, P. Roche, D.C. Glattli, N. Kumada, F.D. Parmentier, and P. Roulleau, submitted (https://arxiv.org/abs/2011.04958(2020))
Composite solid electrolytes for all-solid-state sodium batteries

SL-DRF-21-0385

Research field : Physical chemistry and electrochemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire d’étude des éléments légers

Saclay

Contact :

Saïd Yagoubi

Thibault CHARPENTIER

Starting date : 01-10-2021

Contact :

Saïd Yagoubi
CEA - DRF/IRAMIS/NIMBE/LEEL

+ 33 1 69 08 42 24

Thesis supervisor :

Thibault CHARPENTIER
CEA - DRF/IRAMIS/NIMBE/LSDRM

33 1 69 08 23 56

Personal web page : http://iramis.cea.fr/Pisp/said.yagoubi/

Laboratory link : http://iramis.cea.fr/nimbe/leel/

More : http://iramis.cea.fr/nimbe/lsdrm/

Rechargeable sodium metal all-solid-state batteries (SMSSBs) have a significant cost advantage for large-scale stationary storage and electric mobility owing to the widespread availability of Na in the oceans. However, safety issues caused by the growth of Na dendrites remain during the cycling and restrict practical applications of that technology.



The barriers to overcome allowing the development of SMSSBs consist mainly in the development of high performance solid electrolytes (cationic conduction at ambient temperature close to 1mS.cm-1, high transference number, wide electrochemical window, superior thermal stability and dendrite suppression). In past decades, various kinds of solid electrolytes, such as organic polymers and inorganic ceramics electrolytes have been explored. These electrolytes have different advantages, but their unique limitations hinder their individual practical application.



A great part of the work in this project will be devoted to the development of solid composite electrolyte materials that can display the advantages of the organic polymers and inorganic ceramics solid electrolytes and compensate each other regarding their drawbacks. Combination of multi-scale characterization, electrochemical, structural, spectroscopic and analytical techniques will deepen the understanding of the sodium dynamics through structured networks of the battery.





Keywords: solid electrolyte, ceramic, polymer, composite, all-solid-state battery, interfaces, multi-scale Na+ dynamic characterization, sodium dendrite, ionic conductivity, transference number, thermal stability, solid-state NMR, XRD, EIS.

High Energy Supercapacitors and pseudo-supercapacitors based on p- and n-dopable materials

SL-DRF-21-0877

Research field : Physical chemistry and electrochemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Edifices Nanométriques

Saclay

Contact :

Mathieu PINAULT

Starting date : 01-05-2021

Contact :

Mathieu PINAULT
CEA - DRF/IRAMIS/NIMBE/LEDNA

01-69-08-91-87

Thesis supervisor :

Mathieu PINAULT
CEA - DRF/IRAMIS/NIMBE/LEDNA

01-69-08-91-87

Personal web page : http://iramis.cea.fr/Pisp/mathieu.pinault/

Laboratory link : http://iramis.cea.fr/nimbe/ledna/

More : https://www.u-cergy.fr/fr/laboratoires/lppi/themes-de-recherche/theme-ii.html

To allow the development of carbon-free energies, the storage of electricity is one of the biggest challenges. In this context, the use of nanomaterials specifically organized at the nanoscale such as vertically aligned carbon nanotube mats (VACNTs) is very promising. New pseudocapacitive electrode materials based on vertically aligned carbon nanotubes (VACNT) modified by electronically conductive polymers have demonstrated their interest in producing supercapacitors thus validating the interest of such a configuration (alignment and regular spacing between nanotubes in the material) in terms of energy gain and especially power of the supercapacitor.

This thesis project is part of a partnership between the NIMBE/LEDNA laboratory (CEA-CNRS UMR3685), the LPPI of Cergy Paris University and the NawaTechnologies company. We will develop the controlled growth of aligned CNT on thin aluminum current collectors compatible with industrial use. Our innovative approche will be based on the use of bio-based precursors and on the nature and composition of the reactive gas phase. Given the application, we want to master the characteristics of the mats resulting from these new synthesis conditions, the latter having a crucial role on the capacitance of the electrodes, and therefore the energy density stored in the supercapacitor devices.
Fundamental understanding and development of concentrated aqueous electrolyte for Mg batteries

SL-DRF-21-0413

Research field : Physical chemistry and electrochemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire d’étude des éléments légers

Saclay

Contact :

Magali GAUTHIER

Sophie LE CAER

Starting date : 01-10-2021

Contact :

Magali GAUTHIER
CEA - DRF/IRAMIS/NIMBE/LEEL

01 69 08 45 30

Thesis supervisor :

Sophie LE CAER
CNRS - DRF/IRAMIS/NIMBE/LIONS

01 69 08 15 58

Personal web page : http://iramis.cea.fr/nimbe/Pisp/magali.gauthier/

Laboratory link : http://iramis.cea.fr/nimbe/leel/

Aqueous batteries were long believed to be constrained by the stability window of water (1.23 V), but this is no longer true thanks to water-in-salt electrolytes (WISEs). This concept, implying highly concentrated aqueous solutions, led to an extraordinary increase of the voltage window of lithium aqueous batteries. It is mainly explained by the absence of free water molecules and by the crucial role of the anion-based interface. While WISEs open the way for sustainable systems, these solutions only use expensive and toxic salts. To widen the spectrum of chemistries and look for more sustainable elements, one can envision magnesium and associated salts: safer, less expensive, more abundant than lithium and bearing two electrons. Yet, the sole state-of-the-art water-in-salt aqueous Mg battery improves only slightly the voltage window to 2 V, without clear understanding of the mechanisms at work. Rationalizing reactivity of water-in-salt solutions on a fundamental level is critical to design efficient strategies to increase the voltage window of concentrated aqueous Mg batteries.



The thesis will firstly consist in a comprehensive approach including pioneering experiments such as radiolysis and synchrotron X-Ray absorption spectroscopy, and secondly in the development of innovative electrolytes solutions.
Metabolomic profiles by sensitivity enhanced NMR using parahydrogen

SL-DRF-21-0406

Research field : Physical chemistry and electrochemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Structure et Dynamique par Résonance Magnétique (LCF)

Saclay

Contact :

Gaspard HUBER

Starting date : 01-10-2021

Contact :

Gaspard HUBER
CEA - DRF/IRAMIS/NIMBE/LSDRM

01 69 08 64 82

Thesis supervisor :

Gaspard HUBER
CEA - DRF/IRAMIS/NIMBE/LSDRM

01 69 08 64 82

Personal web page : http://iramis.cea.fr/Pisp/gaspard.huber/

Laboratory link : http://iramis.cea.fr/nimbe/lsdrm/

Metabolomics is the science that relates to the analysis of metabolites, the small molecules (less than 1500 Da) present in organisms. It helps to understand the functioning of these organisms, and to detect, identify or even quantify metabolites that sign a given pathological state or a stress. Nuclear Magnetic Resonance (NMR) is a complementary technique to mass spectrometry (MS) to analyze complex mixtures of metabolites. However, due to its low sensitivity, NMR is not used as much as MS. Different techniques exist for increasing the NMR signal. One of them takes advantage of the special properties of parahydrogen, a spin isomer of dihydrogen gas. Recently, a method based on parahydrogen, called SABRE-Relay, has been invented. In an aprotic medium, it allows the increase of sensitivity of signals of any molecule comprising at least one mobile proton.



The thesis consists in developing the methodology of the SABRE-Relay method when it is applied to cellular metabolic extracts or to biofluids, a large proportion of metabolites comprising at least one labile proton. The objective is to propose new metabolic profiles, offering a greater sensitivity and specificity, compared to conventional profiles by NMR, for a better detection, identification or even quantification of the solutes.

Large-angular momentum atoms with two active electrons : static electric field effects

SL-DRF-21-0392

Research field : Plasma physics and laser-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers

Physique à Haute Intensité

Saclay

Contact :

Michel POIRIER

Starting date : 01-10-2021

Contact :

Michel POIRIER
CEA - DRF/IRAMIS/LIDyL/PHI

+33 (0)1 69 08 46 29

Thesis supervisor :


-


Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=poirier

Laboratory link : http://iramis.cea.fr/lidyl/MHDE/

Statistical methods for the analysis of complex spectra in hot plasmas: applications in fusion science and astrophysics

SL-DRF-21-0436

Research field : Plasma physics and laser-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers

Physique à Haute Intensité

Saclay

Contact :

Michel POIRIER

Starting date : 01-10-2021

Contact :

Michel POIRIER
CEA - DRF/IRAMIS/LIDyL/PHI

+33 (0)1 69 08 46 29

Thesis supervisor :

Michel POIRIER
CEA - DRF/IRAMIS/LIDyL/PHI

+33 (0)1 69 08 46 29

Personal web page : http://iramis.cea.fr/LIDYL/Phocea/Membres/Annuaire/index.php?uid=poirier

Laboratory link : http://iramis.cea.fr/LIDYL/MHDE

A vast range of topics in physics such as the star internal structure, the X-ray emission of accretion disks, the dynamics of inertial confinement fusion, or new radiation sources requires an accurate knowledge of the radiative properties of hot plasmas. Such plasmas exhibit spectra consisting of a large number of lines often merging in unresolved arrays. Statistical methods are used for the interpretation of such spectra.



Using second quantization and tensor algebra techniques, one may obtain quantities such as the average and variance of transition energies inside these unresolved arrays. Though a wide literature exists on this subject, certain types of transitions, e.g., magnetic dipole transitions inside a given configuration or processes involving several electron jumps, have not been considered up to now. In addition to this analytical study, a numerical work involving the Flexible Atomic Code will be proposed for this thesis. This study will concern plasmas either at thermodynamic equilibrium, or out of equilibrium, where level population is obtained by solving a system of kinetic equations.



This research program requires a deep knowledge in quantum physics and in atomic physics in plasmas. Several applications may be foreseen: interpretation of recent opacity measurements performed on LULI2000 laser at Ecole Polytechnique, extreme-UV source optimization for nanolithography, determination of radiative power losses in a tungsten plasma to characterize tokamak operation, or the open subject of the characterization of photoionized silicon plasma analyzed in Sandia Z-pinch in connection with astrophysical observations.
Development and benchmarking of novel AMR-PIC methods for the realistic 3D modelling of light-matter and light-vacuum interactions at extreme intensities

SL-DRF-21-0460

Research field : Plasma physics and laser-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers

Physique à Haute Intensité

Saclay

Contact :

Henri VINCENTI

Starting date : 01-10-2021

Contact :

Henri VINCENTI
CEA - DRF/IRAMIS/LIDyL/PHI

0169080376

Thesis supervisor :

Henri VINCENTI
CEA - DRF/IRAMIS/LIDyL/PHI

0169080376

Personal web page : http://iramis.cea.fr/Pisp/henri.vincenti/

Laboratory link : http://iramis.cea.fr/LIDYL/PHI/

Nowadays, the major challenge of high-field physics or Ultra-High Intensity (UHI) physics is to design a very intense light source capable of exploring new regimes of Strong-Field Quantum Electrodynamics (SF-QED) that are currently out of reach of conventional particle accelerators. The most famous example occurs above 10^29W/cm^2 (the so-called Schwinger limit) around which vacuum breaks down and e-/e+ pairs can be produced out of vacuum. Actually, light-matter interactions at extreme intensities (>10^25W/cm^2) are entirely dominated by SF-QED processes. Such physical regimes are only accessible in the extreme astrophysical events and could reveal new physics beyond the standard model (such as the presence of axions or millicharged fermions). Being able to reproduce and control them in the lab represents a huge fundamental interest.



Yet, the most intense light source on earth (presently, high-power PetaWatt -PW- lasers) only deliver intensities around 10^22W/cm^2. Reaching the Schwinger limit therefore requires a paradigm shift that we recently proposed in the Physics at High Intensity (PHI) group at CEA. Our solution consists in using a remarkable optical component, generated by a high-power laser itself when interacting with a solid target and known as an ’optically-curved relativistic plasma mirror’. Upon reflection on such a curved mirror, the reflected laser light is strongly intensified due to a temporal compression by Doppler effect and a spatial compression by focusing to tinier spots than the ones possible with the incident light. The PHI group recently proposed to use the plasma mirror optical deformation by the incident laser radiation pressure to tightly focus the reflected light. Preliminary 3D simulations show that intensities of 10^25W/cm^2 can be reached with this scheme at plasma mirror focus. At such intensities, yet unexplored SF-QED processes would occur during the interaction of the reflected field with matter. This constitutes the first milestone towards the Schwinger limit.



Now, the major challenge to reach the Schwinger limit is to design novel realistic schemes to optically-curve the plasma mirror surface more strongly than with radiation pressure. In this context, the candidate will develop and validate numerically these novel schemes with Particle-In-Cell (PIC) codes. As the simulations envisaged are extremely costly in terms of computing time, the candidate will first have to develop and benchmark a new Adaptative Mesh Refinement (AMR) method developed by the group of Dr. J-L Vay at Lawrence Berkeley National Lab (LBNL), in which the first phase of the PhD will start. During the second phase (at CEA);, the candidate will use the code to validate the new schemes and answer the following questions: what are the optimal laser-plasma conditions to reach the Schwinger limit? At which intensities does the reflected field start to produce e-/e+ pairs? Are these pairs detectable? How to find clear signatures of the achieved intensities in experiments? The candidate will also support the interpretation of the very first QED experiments performed with plasma mirrors during his PhD.
Design of a high-precision electron injector for the next generation of laser-plasma based particle accelerators

SL-DRF-21-0462

Research field : Plasma physics and laser-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers

Physique à Haute Intensité

Saclay

Contact :

Fabien QUÉRÉ

Henri VINCENTI

Starting date : 01-10-2021

Contact :

Fabien QUÉRÉ
CEA - DRF/IRAMIS/LIDyL/PHI

01.69.08.10.89

Thesis supervisor :

Henri VINCENTI
CEA - DRF/IRAMIS/LIDyL/PHI

0169080376

Personal web page : http://iramis.cea.fr/Pisp/henri.vincenti/

Laboratory link : http://iramis.cea.fr/LIDYL/PHI/

A major challenge faced at present by the accelerator community is to shrink the size of particle accelerators to enable the next generation of TeV electron-positron colliders. A very promising candidate in this regard are laser Wakefield Accelerators (LWFA) produced when a high-power laser is focused on a gas jet. These accelerators can deliver high accelerating gradients of 100 GV/m and have already demonstrated electron acceleration on up to 10 GeV energies on a cm-scale.



However, important limitations need to be addressed before enabling the use of LWFAs as medical devices or for building compact electron/positron high-energy colliders and X-ray Free Electron Lasers (X-FEL) light sources. In particular a major impediment of these accelerators is that they currently suffer from low charge at high-energy (10pC/bunch above 4GeV) far below the charge they could sustain (up to 50nC) or the ones obtained with conventional RF accelerators (> nC/bunch). In these conditions, building a LWFA-based collider mandating high number of collisions and hence much higher charge would require upgrading multi-TeraWatt or PetaWatt lasers repetition rates from present 1Hz to tens of kHz, to reach much higher average currents, which is beyond present laser technology. Solutions to increase the charge at high-energy with present injection techniques have been proposed (e.g. by using a high gas density pre-injection stage coupled to a second low-density acceleration stage with intermediate beam transport). Yet, scaling up charge to 1-10nC at high-energy (GeV) with these techniques is far from acquired and might degrade crucial beam features (e.g. emittance, energy spread) that would be a severe limitation for many applications necessitating high beam quality (e.g. X-FEL).



In this context, this PhD thesis aims at devising alternative and novel schemes using our kinetic numerical codes PICSAR and WARPX that should enable compact accelerators with up to 1-10nC/bunch up to multi-GeV energy levels while preserving a high beam quality. A very promising one would be to use plasma mirrors as electron injectors. Plasma mirrors are overdense plasmas formed when a high power laser is focused on a solid target. As such, they can provide a very large reservoir of electrons that could be coherently accelerated by the incident laser and injected into a LWFA. Preliminary simulations show that placing a plasma mirror just before a gas jet could allow for a highly localized spatio-temporal injection of sub-femtoseconds electron bunches in a LWFA. This highly localized injection is the pre-requisite to obtain very high quality LWFA electron bunches and seems to surpass by an order of magnitude (in terms of charge and beam quality) all schemes proposed so far in the literature.



Leveraging on the numerical tools developed by the Physics at High Intensity Group in the last five years, the goal of this PhD thesis will be to design numerically a high-quality electron injector for LWFA using plasma mirrors. It will include several important milestones:



(i) A first phase where preliminary simulations will be refined and a detailed proof-of-concept of the injection will be established (A patent will be written),



(ii) A second phase where a model of electron injection from the plasma mirror into the LWFA is developed and optimal regimes are found (in terms of laser-plasma parameters). The optimization step will involve the development of surrogate models using deep neural networks,



(iii) A final phase involving the coupling with experiments where the full experimental set-up will be numerically simulated. This will involve the coupling of 2D/3D hydrodynamic simulations (to efficiently model the gas density profile at the gas-plasma mirror interface) with kinetic simulations (to model injection in the LWFA).



Succeeding in this task would alleviate by several orders of magnitude constraints in terms of required laser repetition rate for building a compact collider. In addition, achieving an ultra-compact accelerator with high-charge and high beam-quality could be used to produce table-top ultra-short electron, X-FEL or Bremsstrahlung/Compton X-ray light sources that are paramount to many applications such as cancer treatment, femtosecond chemistry, radiobiology, radiotherapy or industrial radiography.

Attosecond pulses generated in active gratings for the detection of helicoidal dichroisms

SL-DRF-21-0232

Research field : Radiation-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers

Attophysique (ATTO)

Saclay

Contact :

Thierry Ruchon

Starting date : 01-09-2021

Contact :

Thierry Ruchon
CEA - DRF/IRAMIS/LIDyL/ATTO

0169087010

Thesis supervisor :

Thierry Ruchon
CEA - DRF/IRAMIS/LIDyL/ATTO

0169087010

Personal web page : http://iramis.cea.fr/LIDYL/Pisp/thierry.ruchon/

Laboratory link : http://iramis.cea.fr/LIDYL/atto/

More : http://attolab.fr/

Light in the extreme ultraviolet (XUV) is a universal probe of mater, may it be in diluted or condensed phase: photons associated with this spectral range carry energy of 10 to 100 eV, sufficient to directly ionize atoms, molecules or solids. Large scale instruments such as synchrotrons or the lately developed free electron lasers (FEL) work in this spectral range and are used to both study fundamental light matter interaction and develop diagnosis tools. However these instruments do not offer the temporal resolution require to study light matter interactions at their ultimate timescales, which is in the attosecond range (1as = 10-18s). An alternative is offered by the recent development of XUV sources based on high order harmonic generation (HHG). They are based on the extremely nonlinear interaction of a femtosecond intense laser beam with a gas target. Our laboratory has pioneered the development, control and design of these sources providing XUV attosecond pulses.



During this PhD project, we will develop specific setups to allow these attosecond pulse to carry angular momenta, may it be spin or orbital angular momenta. This will open new applications roads through the observations of currently ignored spectroscopic signatures. On the one hand, the fundamental aspects of the coupling of spin and orbital angular momentum of light in the highly nonlinear regime will be investigated, and on the other hand, we will tack attosecond novel spectroscopies, may it be in diluted or condensed phase. In particular, we will chase helical dichroism, which manifest as different absorptions of beams carrying opposite orbital angular moments. These effects are largely ignored to date.

The student will acquire practical knowledge about lasers, in particular femtosecond lasers, and hands on spectrometric techniques of charged particles. He/she will also study strong field physical processes which form the basis for high harmonic generation. He/she will become an expert in attosecond physics. The acquisition of analysis skills, computer controlled experiments skills will be encouraged although not required.



Full and detailed subject at http://iramis.cea.fr/LIDYL/Pisp/thierry.ruchon/.

Coulomb phase in Rare-Earth hyperkagome networks

SL-DRF-21-0383

Research field : Radiation-matter interactions
Location :

Laboratoire Léon Brillouin

Groupe 3 Axes

Saclay

Contact :

SYLVAIN PETIT

Starting date : 01-10-2020

Contact :

SYLVAIN PETIT
CEA - DRF/IRAMIS/LLB

01 69 08 60 39

Thesis supervisor :

SYLVAIN PETIT
CEA - DRF/IRAMIS/LLB

01 69 08 60 39

Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=spetit

Laboratory link : http://www-llb.cea.fr/NFMQ/

The last decades in solid-state research have seen the rise of rich and novel physics, beyond the Neel paradigm and transcending conventional descriptions based on Landau theory. Frustrated magnetism has contributed to these developments in major ways, through new concepts like the “Coulomb phase”, a highly degenerate state of matter brought to light by the discovery of spin ice in rare-earth pyrochlore networks. In the following PhD proposal, our aim is to use hyperkagome networks of rare earths to further explore and develop this new physics.

SL-DRF-21-0423

Research field : Radiation-matter interactions
Location :

Laboratoire des Solides Irradiés

Laboratoire des Solides Irradiés

Saclay

Contact :

Antonino ALESSI

Valérie VENIARD

Starting date : 01-10-2021

Contact :

Antonino ALESSI
CEA - DRF/IRAMIS/LSI/LSI


Thesis supervisor :

Valérie VENIARD
CNRS - LSI/Laboratoire des Solides Irradiés

01 69 33 45 52

Personal web page : https://www.polytechnique.edu/annuaire/fr/users/antonino.alessi

Laboratory link : https://portail.polytechnique.edu/lsi/fr/equipements/linstallation-sirius

Towards optical cycle dynamics in solids

SL-DRF-21-0407

Research field : Radiation-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers

Attophysique (ATTO)

Saclay

Contact :

Stéphane GUIZARD

Starting date : 01-09-2021

Contact :

Stéphane GUIZARD
CEA - DRF/IRAMIS/LIDyL/ATTO

0169087886

Thesis supervisor :

Stéphane GUIZARD
CEA - DRF/IRAMIS/LIDyL/ATTO

0169087886

Personal web page : http://iramis.cea.fr/Pisp/stephane.guizard/

Laboratory link : http://iramis.cea.fr/LIDYL/ATTO/

More : https://loa.ensta-paristech.fr/research/appli-research-group/

The fundamental TOCYDYS research program aims to probe the dynamics of solids with temporal resolution at the optical cycle scale and to cross the femtosecond resolution limit. We will initially concentrate on insulators such as silica and quartz (SiO2) or sapphire (Al2o3).



The experiments will be carried out on the facilities recently opened at LOA and LIDYL of Equipex Attolab (http://attolab.fr/), where we will have access to phase-stabilized lasers and associated ultra short VUV pulses.



The experiments will consist of exciting the samples with pulses of a few optical cycles (intensity in the range 1012 to 1015 W/cm2) and probing the dynamics by measuring change of reflectivity, in the IR and visible domains, then with attosecond pulse trains in the VUV.



We will have direct access to the physical mechanisms of the material laser interaction and to the initial stages of the electronic relaxation of the solid: multiphoton, tunnel or Zener ionization, modulation of the band gap, inelastic diffusion of the carriers, impact ionization, Auger effect, etc…



During the first part of the program, at the Laboratory of Applied Optics- LOA, the measurements will be made in the visible and near IR domains, with the objective to achieve the resolution of the optical cycle. Then, in the second part, we will construct a set-up for the reflectivity measurement in the VUV domain, capable of recording variations in the amplitude of the probe pulse, but also of the phase using spatial interferometry in the VUV domain.



The TOCYDYS research program received funding from the National Research Agency (ANR) for the period 2020-2023. So the Masters internship is funded. The experimental part will be conducted at LOA in collaboration with Davide Boschetto (https://loa.ensta-paristech.fr/research/appli-research-group/).
Temporal characterization of high order harmonic generation in semi conducting crystals.

SL-DRF-21-0467

Research field : Radiation-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers

Attophysique (ATTO)

Saclay

Contact :

Willem Boutu

Starting date : 01-10-2021

Contact :

Willem Boutu
CEA - DRF/IRAMIS/LIDYL/ATTO

0169085163

Thesis supervisor :

Willem Boutu
CEA - DRF/IRAMIS/LIDYL/ATTO

0169085163

Personal web page : http://iramis.cea.fr/LIDYL/en/Phocea/Pisp/index.php?nom=willem.boutu

Laboratory link : http://iramis.cea.fr/LIDYL/ATTO/

The development of ultrashort lasers, controlled at a sub cycle scale, has given rise to a new discipline of physics, attosecond physics, dedicated to the study of electron dynamics during the matter interaction with the laser. Long limited to the study of gas phase phenomena, high order laser harmonic generation in semiconducting crystals opens the way to the study of those ultrafast dynamics in condensed matter. The objective of this PhD thesis is to transpose the techniques of spectral and temporal characterization developed in LIDYL for the gas phase to this new phenomenon, in order to image the electronic band structure in exotic materials such as 2D materials (graphene) or strongly correlated materials (NiO for instance), and to measure the attosecond electron currents generated during the interaction. This experimental work will take place on the new NanoLight platform in a brand new laboratory. However, it will benefit from a strong theoretical and numerical support from our collaborators at MPSD in Hamburg.
Attosecond imaging of electronic wavepackets in molecular gases

SL-DRF-21-0453

Research field : Radiation-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers

Attophysique (ATTO)

Saclay

Contact :

Pascal SALIERES

Starting date : 01-10-2021

Contact :

Pascal SALIERES
CEA - DRF/IRAMIS/LIDyL/ATTO

0169086339

Thesis supervisor :

Pascal SALIERES
CEA - DRF/IRAMIS/LIDyL/ATTO

0169086339

Personal web page : http://iramis.cea.fr/Pisp/pascal.salieres/

Laboratory link : http://iramis.cea.fr/LIDYL/atto/

More : http://attolab.fr/

Summary :

The student will first generate XUV attosecond pulses using an intense Titanium:Sapphire laser (ATTOLab Excellence Equipment), and then use them to investigate the ionization dynamics of molecular gases: electron ejection, electronic rearrangements in the ion, charge migration, quantum decoherence…



Detailed summary :

Recently, the generation of sub-femtosecond pulses, so-called attosecond pulses (1 as=10-18 s), has made impressive progress. These ultrashort pulses open new perspectives for the exploration of matter at unprecedented timescale. Their generation result from the strong nonlinear interaction of short intense infrared (IR) laser pulses (~20 femtoseconds) with atomic or molecular gases. High order harmonics of the fundamental frequency are produced, covering a large spectral bandwidth in the extreme ultraviolet (XUV) range. In the temporal domain, this coherent radiation forms a train of 100 attosecond pulses [1]. In order to generate isolated pulses, it is necessary to confine the generation in an ultrashort temporal window, which implies the development of various optical confinement techniques.



With such attosecond pulses, it becomes possible to investigate the fastest dynamics in matter, i.e., electronic dynamics that occur naturally on this timescale. Attosecond spectroscopy thus allows studying fundamental processes such as photo-ionization, in order to answer questions such as: how long does it take to remove one electron from an atom or a molecule? The measurement of such tiny ionization delays is currently a “hot topic” in the scientific community. In particular, the study of the ionization dynamics close to resonances gives access to detailed information on the atomic/molecular structure, such as the electronic rearrangements in the remaining ion upon electron ejection [2].



The objective of the thesis is first to generate attosecond pulses with duration and central frequency adequate for the excitation of various molecular systems. The objective is then to measure the instant of appearance and the angular distribution of the charged particles, electrons and ions. These spatial and temporal informations will allow the reconstruction of the full 3D movie of the electron ejection, as well as of the hole migration in the ion leading to fragmentation. Finally, quantum decoherence, e.g., induced by ion-photoelectron entanglement, will be studied using a new technique recently demonstrated in our laboratory [3].



The experimental work will include the development and operation of a setup installed on the FAB1 laser of the ATTOLab Excellence Equipment allowing: i) the generation of attosecond XUV radiation, ii) its characterization using quantum interferometry, iii) its use in photo-ionization spectroscopy. The theoretical aspects will also be developed. The student will be trained in ultrafast optics, atomic and molecular physics, quantum chemistry, and will acquire a good mastery of charged particle spectrometry. A background in ultrafast optics, nonlinear optics, atomic and molecular physics is required.

Part of this work will be performed in collaboration with partner French and European laboratories through joint experiments in the different associated laboratories (Milano, Lund).



References :

[1] Y. Mairesse, et al., Science 302, 1540 (2003)

[2] V. Gruson, et al., Science 354, 734 (2016)

[3] C. Bourassin-Bouchet, et al., Phys. Rev. X 10, 031048 (2020)

Structure and properties of dense phases of amorphous silica

SL-DRF-21-0463

Research field : Radiation-matter interactions
Location :

Laboratoire des Solides Irradiés

Laboratoire des Solides Irradiés

Saclay

Contact :

Nadege OLLIER

Starting date : 01-09-2021

Contact :

Nadege OLLIER
CEA - DRF/IRAMIS/LSI

01 69 33 45 18

Thesis supervisor :

Nadege OLLIER
CEA - DRF/IRAMIS/LSI

01 69 33 45 18

Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=ollier

Laboratory link : https://portail.polytechnique.edu/lsi/fr/recherche/defauts-desordre-et-structuration-de-la-matiere

Nowadays, many technologies are based on optical or optoelectronic devices integrating silica glasses because of its exceptional properties (ultra-transparency in the UV-NIR range, high mechanical resistance, low thermal expansion). Understanding the behavior of silica under extreme conditions (high pressures, irradiation) remains an issue for a large number of applications in the field of nuclear and space. It is possible by indentation or by hydrostatic compression to permanently densify the silica to limit values around 20% (at 25 GPa) because of the large free volume of this glass. Densifying silica by using irradiation is also possible. We recently showed the existence of a single polymorph of silica (density 2.26 g / cm3) obtained whatever the initial state of the silica after irradiation at very high doses (typ> 10 GGy for electrons of 2.5 MeV). But at this stage, it is unclear if this amorphous phase is unique and identical to the so-called "metamict" phase obtained after irradiation and amorphization of the crystalline polymorphs of silica (quartz, coesite, etc.). The PhD will focus on dense silica phases such as this mectamict phase and thin layer of silica to characterize their structure and properties like mechanical properties.
Thermal conductivity in 1D spin chains

SL-DRF-21-0384

Research field : Radiation-matter interactions
Location :

Laboratoire Léon Brillouin

Groupe 3 Axes

Saclay

Contact :

SYLVAIN PETIT

Loreynne PINSARD

Starting date : 01-10-2021

Contact :

SYLVAIN PETIT
CEA - DRF/IRAMIS/LLB

01 69 08 60 39

Thesis supervisor :

Loreynne PINSARD
Université PARIS XI - ICMMO


Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=spetit

Laboratory link : http://www-llb.cea.fr/NFMQ/

The increasing miniaturization and integration of today's electronics lead to an increase in heat dissipation problems. One of the solutions being considered is the use of materials capable of conducting heat to a heat sink, quickly and unidirectionally, for greater efficiency. In this context, the use of low dimensional magnetic materials is an interesting approach.



The transport of heat by magnetic excitations, predicted as early as 1936, was demonstrated in the 1970s in a ferrimagnetic yttrium-iron garnet (YIG). In this case, in the ordered magnetic phase at low temperature (T < 10K), the magnetic contribution to heat transport is due to classical spin waves (or magnons). The first signature of a magnetic thermal transport at high temperature (T > 50K) was observed for the first time in a low-dimensional quantum compound, KCuF3, as early as 1975. But it was the Heisenberg one-dimensional (1D) antiferromagnetic compounds and the discovery of a giant magnetic thermal conductivity in the Sr14Cu24O41 quantum spin ladder that really triggered the revival of research in low-dimensional magnetic systems.



In this context, this thesis project is particularly interested in copper oxides (or cuprates) of the form SrCuO2, Sr2CuO3, CaCuO2 et Ca2CuO3. The aim of this project is to better understand the mechanisms governing thermal transport. It includes, in addition to sample synthesis, a series of characterization and analysis of thermal conductivity as well as of the excitation spectrum (lattice and magnetic) by neutron scattering.
Relation between cancer stem cells and hypoxia in tumour radio-resistance: benefits of hadrontherapy in chondrosarcoma and glioblastoma treatment

SL-DRF-21-0461

Research field : Radiobiology
Location :

Centre de recherche sur les Ions, les Matériaux et la Photonique

Centre de recherche sur les Ions, les Matériaux et la Photonique

Saclay

Contact :

Francois Chevalier

Starting date : 01-10-2021

Contact :

Francois Chevalier
CEA - DRF/IRAMIS/CIMAP

02 31 45 45 64

Thesis supervisor :

Francois Chevalier
CEA - DRF/IRAMIS/CIMAP

02 31 45 45 64

Personal web page : http://cimap.ensicaen.fr/spip.php?article206

Laboratory link : http://cimap.ensicaen.fr/spip.php?rubrique113

More : http://www.istct.cyceron.fr/index.php/fr/equipes/cervoxy

Tumor initiating cells, also called cancer stem cells (CSCs), are largely responsible for the relapse and treatment failure. These CSCs have an almost unlimited capacity for self-renewal and can differentiate into all populations of cells present in the tumors from which they originate. These two fundamental properties make these cells responsible for tumor growth and recurrence, thus constituting an essential target for the treatment of cancer. Current cancer treatments and particularly radiotherapy seem to be ineffective against these CSCs and even could increase their proportion.



This project focuses on three biological pathways potentially involved in radiation resistance of CSCs: DNA repair, the hypoxic microenvironment and antioxidant capacity. These pathways will be modified in vitro according to different combinations (single or double inhibition) in two models of cancer stem cells (chondrosarcoma and glioblastoma) in association with irradiations of different types (X-rays, protons, carbon ions).



The aim is to gain a better understanding of how hadrons, together with other therapies, can be used to increase the chances of recovery from radiation-resistant cancers. In parallel, targeting the tumor microenvironment and the response to oxidative stress in combination with, for example, a DNA repair inhibitor, may lead to the discovery of new therapeutic approaches capable of helping to solve the most serious problem in oncology. : tumor resistance and relapses.

Spontaneous stochasticity and singularities in turbulence

SL-DRF-21-0370

Research field : Soft matter and complex fluids
Location :

Service de Physique de l’Etat Condensé

Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes

Saclay

Contact :

Bérengère DUBRULLE

Starting date : 01-10-2021

Contact :

Bérengère DUBRULLE
CNRS - DRF/IRAMIS/SPEC/SPHYNX

0169087247

Thesis supervisor :

Bérengère DUBRULLE
CNRS - DRF/IRAMIS/SPEC/SPHYNX

0169087247

Personal web page : http://iramis.cea.fr/Pisp/berengere.dubrulle/index.html

Laboratory link : http://iramis.cea.fr/spec/sphynx/

It is known since Lorentz that the movement of fluids, especially the atmosphere and the ocean is chaotic: in phase space, two points that were initially close, move exponentially apart, thus producing the famous butterfly effect. What is less known is that these same fluids are victims of an even more violent phenomenon called "spontaneous stochasticity", during which two points in physical space separate algebraically, independently of their initial distance. Mathematicians suspect that this phenomenon, observed in numerical simulations, is created by the existence of singularities in the equations of motion, thus breaking the uniqueness of the solutions. However, to date, there is no experimental demonstration of this phenomenon, nor any proof of its link with singularities or quasi-singularities.



The aim of this thesis is to fill these lacks by using a new experiment called GVK (for "Giant Von Karman"). This experiment has been specially designed to explore particle dynamics and turbulent motions, with a resolution never reached before. In this thesis, experimental measurements will be performed using velocimetric imaging devices, and the data will be analyzed to highlight the phenomenon, and its possible links with quasi-singularities.



The search for singularities in the Euler or Navier-Stokes equations is a well-known problem (cf. AMS Millennium Clay Prize), but recent advances, both numerically and experimentally, bring this problem to the fore once again. In particular, our group has recently highlighted, in a turbulent laboratory flow, the existence of intense non-viscous energy dissipation events that could be associated with the singularities sought by mathematicians (Saw et al, Nature Communication 7 (2016) 12466).



The core of this thesis is experimental, but theoretical developments on out-of-equilibrium physics via multi-fractal formalism and wavelets may be carried out. This thesis will be supervised by A. Cheminet and B. Dubrulle (CNRS). The subject is at the interface between fluid mechanics, mathematics and statistical physics. The thesis requires a solid training as a physicist, in particular in statistical physics, as well as a strong interest for experimentation.
Data driven agent based model for the numerical modeling of human digestion

SL-DRF-21-0424

Research field : Soft matter and complex fluids
Location :

Laboratoire Léon Brillouin

Groupe de Diffusion Neutron Petits Angles

Saclay

Contact :

Fabrice COUSIN

Evelyne LUTTON

Starting date : 01-10-2021

Contact :

Fabrice COUSIN
CEA - DRF/IRAMIS/LLB/MMB

01 69 08 67 73

Thesis supervisor :

Evelyne LUTTON
INRAE - UMR MIA 518

0169086460

Personal web page : www-llb.cea.fr/Pisp/fabrice.cousin/

Laboratory link : www-llb.cea.fr

More : http://evelyne-lutton.fr http://francois-boue.monsite-orange.fr

The proposed PhD will be part of a collaboration between LLB (CEA/CNRS) and INRAE, on the study of the influence of food structure on digestion kinetics, in partnership with Soleil synchrotron (DISCO and SWING lines), CEA-SHFJ (IR4M, MRI imaging) and Bangor University, UK (CS Dpt). An important amount of data was collected through in vitro and in vivo experiments. The in vitro monitoring coupled large (rheology), intermediate (microscopy) and nanometric (SANS-SAXS) scales on different foods, including plant protein gels. In vivo medical imaging (MRI of the digestive tract) made it possible to monitor the position of foods (peas) in the stomach and upper intestine on a macroscopic scale. We wish to valorise these data by a numerical model based on a multi-agent reaction-diffusion approach. Such a scheme will allow us(i) to combine effects at different scales, (ii) to account for the heterogeneity, spatial and temporal, intrinsic to digestion and (iii) to integrate different types of uncertainty (related to the data, the model, the numerical algorithm, and unknown parameters). The approach that will be studied will use different AI and interactive machine learning techniques to link the "in silico" framework to the data. The idea is then to be able to numerically evaluate, in relation to the experimental data, different hypotheses on human digestion mechanisms.
Thermoelectric energy conversion in ferrolfuids for hybrid solar heat collector

SL-DRF-21-0299

Research field : Soft matter and complex fluids
Location :

Service de Physique de l’Etat Condensé

Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes

Saclay

Contact :

Sawako NAKAMAE

Starting date : 01-10-2021

Contact :

Sawako NAKAMAE
CEA - DRF/IRAMIS/SPEC/SPHYNX

0169087538

Thesis supervisor :

Sawako NAKAMAE
CEA - DRF/IRAMIS/SPEC/SPHYNX

0169087538

Personal web page : http://iramis.cea.fr/spec/Phocea/Pisp/index.php?nom=sawako.nakamae

Laboratory link : http://iramis.cea.fr/spec/SPHYNX/

More : https://www.magenta-h2020.eu

Thermoelectric (TE) materials that are capable of converting heat into electricity have been considered as one possible solution to recover the low-grade waste-heat (from industrial waste-stream, motor engines, household electronic appliances or body-heat).



At SPHYNX, we explore thermoelectric effects in an entirely different class of materials, namely, complex fluids containing electrically charged nanoparticles that serve as both heat and electricity carriers. Unlike in solid materials, there are several inter-dependent TE effects taking place in liquids, resulting in Se values that are generally an order of magnitude larger that the semiconductor counterparts. Furthermore, these fluids are composed of Earth-abundant raw materials, making them attractive for future TE-materials that are low-cost and environmentally friendly. While the precise origins of high Seebeck coefficients in these fluids are still debated, our recent results indicate the decisive role played by the physico-chemical nature of particle-liquid interface.



The goal of the PhD project is two-fold. First, we will investigate the underlying laws of physics behind the thermoelectric potential and power generation and other associated phenomena in a special type of complex fluids, namely, ferrofluids (magnetic nanofluids). The results will be compared to their thermos-diffusive properties to be obtained through research collaboration actions. Second, the project aims to develop proof-of-concept hybrid solar-collector devices that are capable of co-generating heat and electricity.



The proposed research project is primarily experimental, involving thermos-electrical, thermal and electrochemical measurements; implementation of automated data acquisition system and analysis of the resulting data obtained. The notions of thermodynamics, fluid physics and engineering (device) physics, as well as hands-on knowledge of experimental device manipulation are needed. Basic knowledge of optics and electrochemistry is a plus. For motivated students, numerical simulations using commercial CFD software can also be envisaged.
Polymer nanocomposite microlattice

SL-DRF-21-0404

Research field : Soft matter and complex fluids
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Interdisciplinaire sur l’Organisation Nanométrique et Supramoléculaire

Saclay

Contact :

Patrick GUENOUN

Valérie GEERTSEN

Starting date : 01-09-2021

Contact :

Patrick GUENOUN
CEA - DRF/IRAMIS/NIMBE/LIONS

01-69-08-74-33

Thesis supervisor :

Valérie GEERTSEN
CEA - DRF/IRAMIS/NIMBE/LIONS

0643360545

Personal web page : http://iramis.cea.fr/Pisp/valerie.geertsen/

Laboratory link : http://iramis.cea.fr/nimbe/lions/

More : http://iramis.cea.fr/Pisp/daniel.bonamy/

Reducing material density is an efficient way to reduce our energy footprint. This can be achieved by replacing massive materials with microlattice materials. Among them, random and hierarchical architectures inspired by the bone structure of birds show isotropic mechanical response and increased tensile strength. Thanks to their small raw material consumption, these metamaterials also meet the circular economy challenges. They are manufactured by 3D printing and can be compacted at the end of their life cycle. Among the fabrication technologies, organic liquid resin UV polymerization printing is the most promising as nanoparticles can be introduced in the resins to modulate metamaterials properties. Unfortunately, such a fabrication consumes organic solvent and remain empirical as extensively relying on trial-and-error printing procedures.



The PhD-thesis program proposed here focuses on the development of polymeric nanocomposite microlattice structures, from the resin formulation to the mechanical property characterization through the printing and post-processing stages. This multidisciplinary study bridges science to technology while producing data for a digital twin. The thesis focuses in particular on water-washable acrylate-type resin formulation and on the influence of highly monodisperse silica nanoparticles population on the properties of both plain and structured printed objects. It will result in a better understanding of the entire process and will provide a large dataset of elastic and fracture properties in microlattices to feed numerical modeling.
Data-driven modeling and theory of dense active suspensions

SL-DRF-21-0417

Research field : Soft matter and complex fluids
Location :

Service de Physique de l’Etat Condensé

Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes

Saclay

Contact :

Hugues CHATE

Starting date : 01-10-2021

Contact :

Hugues CHATE
CEA - DRF/IRAMIS/SPEC/SPHYNX

0169087535

Thesis supervisor :

Hugues CHATE
CEA - DRF/IRAMIS/SPEC/SPHYNX

0169087535

Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=chate

Laboratory link : http://iramis.cea.fr/spec/sphynx/

Context : Active Matter – composed of particles that convert energy into mechanical work – is currently the fastest-growing segment of statistical physics, with obvious and multiple connections to living systems. While much has been accomplished, too often the theoretical understanding of experimental phenomena remains rather superficial.



Work plan: We recently developed models of interacting micro-swimmers that are simple, versatile, and numerically efficient. We showed that they can account quantitatively for dense fluids of swarming bacteria [PNAS 116, 777 (2019)]. These models treat short-range interactions effectively. To make the implementation of this data-driven modeling more efficient, we will use AI/ML techniques to learn both the effective local interactions and the optimal set of parameters from respectively local and global experimental data. The second stage of the project will consist in deriving continuous theories from these particle-level models (using concepts borrowed from kinetic theory), and to learn optimal values of their transport coefficients so as to reach quantitative agreement at continuous level.



Expected results: Efficient numerical twins of dense bacterial fluids, data-driven quantitative theories for these systems. Novel methodology for quantitative modeling of active suspensions and active materials.

Fate of therapeutical lipidic nanoassemblies in a biomimetic medium

SL-DRF-21-0416

Research field : Soft matter and complex fluids
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Interdisciplinaire sur l’Organisation Nanométrique et Supramoléculaire

Saclay

Contact :

Frédéric GOBEAUX

Fabienne TESTARD

Starting date : 01-10-2021

Contact :

Frédéric GOBEAUX
CEA - DRF/IRAMIS/NIMBE/LIONS

01 69 08 55 21

Thesis supervisor :

Fabienne TESTARD
CEA - DRF/IRAMIS/NIMBE/LIONS

01 69 08 96 42

Personal web page : http://iramis.cea.fr/nimbe/Pisp/fabienne.testard/

Laboratory link : http://iramis.cea.fr/nimbe/lions/

More : http://iramis.cea.fr/Pisp/frederic.gobeaux/

It is now well-established that upon introduction of mineral nanoparticles in a biological medium, proteins adsorb on their surface (often referred to as “protein corona”), giving them a new biological identity that will define their bioactivity. However, the fate of soft nanoparticles (e.g. polymeric nanoparticles or lipidic self-assemblies like cubosomes) has garnered much less attention. Recent studies for examples suggest that blood proteins disassemble lipidic nanoassemblies rather than adsorb on their surface, which has consequences on the release and transport of the active ingredient. The second important factor to examine is the hydrodynamic flux.



In this PhD project, we will address the role of shearing on the soft nanoparticles and on their interaction with biological fluids in order to model their behaviour in the blood circulation.
Design and characterization of multistimulable hydrogels

SL-DRF-21-0440

Research field : Soft matter and complex fluids
Location :

Laboratoire Léon Brillouin

Groupe Interfaces et Matériaux

Saclay

Contact :

Fabrice COUSIN

Starting date :

Contact :

Fabrice COUSIN
CEA - DRF/IRAMIS/LLB/MMB

01 69 08 67 73

Thesis supervisor :

Fabrice COUSIN
CEA - DRF/IRAMIS/LLB/MMB

01 69 08 67 73

Personal web page : http://iramis.cea.fr/Pisp/fabrice.cousin/

Laboratory link : http://iramis.cea.fr/LLB/MMB

The aim of the project is the design and characterization of smart" hydrogels that can respond to different types of stimuli: pH, ionic strength, temperature but also shear. The idea is to use self-assemblies of surfactants as crosslinking nodes, forming the hydrogels with polymers terminated by a short alkyl anchor allowing their insertion into the hydrophobic core of the self-assemblies. The phase transitions of self-assemblies of surfactants should make it possible to obtain systems for which the number and the morphology of the crosslinking nodes (spherical or discotic micelles, multi-lamellar tubes for example, etc.) can be tuned in situ by playing on physicochemical parameters such as temperature, ionic strength or pH. By using polymers whose conformation is itself tunable by these physicochemical parameters, we will obtain hydrogels which will thus be able to respond to stimuli in a synergistic manner via the nodes and via the chains. These gels will be characterized by coupling structural measurements by ray scattering (neutrons, X-rays, at rest and in traction) with macroscopic rheological measurements.
Theoretical studies of novel graphene based nanostructures

SL-DRF-21-0343

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l’Etat Condensé

Groupe Mésocopie Modélisation et Thermoélectricité

Saclay

Contact :

Yannick DAPPE

Starting date : 01-05-2020

Contact :

Yannick DAPPE
CNRS - DRF/IRAMIS/SPEC/GMT

+33 (0)1 69 08 84 46

Thesis supervisor :

Yannick DAPPE
CNRS - DRF/IRAMIS/SPEC/GMT

+33 (0)1 69 08 84 46

Personal web page : http://iramis.cea.fr/Pisp/yannick.dappe/

Laboratory link : http://iramis.cea.fr/spec/GMT/

A PhD position is open in the “Groupe de Modélisation et Théorie” at SPEC (UMR 3680 CNRS – CEA Saclay).

This theoretical work is dedicated to the study of new carbon materials like graphene nano-meshes (perfectly periodical network of sized holes within the lattice) shape/size controlled graphene flakes and graphene nanoribbons. All these structures are of crucial interest in several modern issues like optics, nanoelectronics and spintronics.

It consists in the study of both atomistic and electronic structures of these new materials, aiming to determinate electronic transport and optical properties.

Investigations will be performed with Density Functional Theory (DFT) and tight-binding models. The goal is to determine electronic structure at different levels of accuracy, enabling robustness of predictions for a large range of systems sizes. From this well established electronic structure, the transport properties will firstly be determined within a Green functions formalism. Scanning tunneling microscopy (STM) images as well as tunnel current spectroscopies will also be simulated, in order to compare and analyze experimental data.

Optical response of these materials will be studied from previous DFT results. Absorption or luminescence properties will be calculated help to a combined DFT/tight-binding formalism. A large part of the work here will consist in the development of the tight binding model needed to study the largest structures.

The research performed during this project will be performed within a long-time collaboration network involving experimental teams located in the Saclay area: chemistry groups at CEA-Nimbe and ICMMO, STM/STS at ISMO and optics measurements at LAC.

The PhD student theoretical work will then be performed within this collaboration, ensuring excellent experiment/theory feedbacks and comparisons.

The candidate must have followed condensed matter studies, with a numerical and theoretical background. He/she also should show interest in experimental techniques involved in this project.
Neuromorphic computing with nonlinear spin-wave dynamics

SL-DRF-21-0418

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l’Etat Condensé

Laboratoire Nano-Magnétisme et Oxydes

Saclay

Contact :

Grégoire de Loubens

Starting date : 01-10-2020

Contact :

Grégoire de Loubens
CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 71 60

Thesis supervisor :

Grégoire de Loubens
CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 71 60

Personal web page : http://iramis.cea.fr/Pisp/gregoire.deloubens

Laboratory link : http://iramis.cea.fr/spec/Phocea/Vie_des_labos/Ast/ast_groupe.php?id_groupe=179

More : https://cordis.europa.eu/project/id/899646/fr

Although neuromorphic computing is a major contributor to the development of artificial intelligence, there are still few hardware implementations of neural networks. In particular, it is difficult to create such networks with a very large number of interconnections between physical neurons, which are nevertheless necessary to achieve the performance promised by this type of architecture. In this thesis, we propose to explore an original path that could ultimately solve this problem of hyperconnectivity. In magnetic microstructures, the eigenmodes of excitation (spin waves) are coupled with each other via nonlinear interactions. The idea is to use this strongly nonlinear dynamic system to perform neuromorphic computational tasks. The spin wave modes, defined in reciprocal space, act as neurons, while their non-linear interactions, whose amplitudes are controlled by the population in each mode, act as synapses. By experimentally studying the mechanisms of energy redistribution between spin waves in ferromagnetic microstructures under different excitation regimes, and by relying on micromagnetic simulations of magnetization dynamics, the objective of this thesis will be to identify configurations allowing an efficient hardware implementation to perform neuromorphic computing, which would be useful, among other things, for processing telecommunication signals.
Catalytically activated hematite nanorod photoanodes for more efficient hydrogen production by solar water splitting

SL-DRF-21-0388

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l’Etat Condensé

Laboratoire Nano-Magnétisme et Oxydes

Saclay

Contact :

Dana STANESCU

Cindy ROUNTREE

Starting date :

Contact :

Dana STANESCU
CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 75 48

Thesis supervisor :

Cindy ROUNTREE
CEA - DRF/IRAMIS/SPEC/SPHYNX

+33 1 69 08 26 55

Personal web page : http://iramis.cea.fr/Pisp/dana.stanescu/

Laboratory link : http://iramis.cea.fr/spec/lno/

More : https://www.synchrotron-soleil.fr/fr/lignes-de-lumiere/hermes; https://www.pluginlabs-universiteparissaclay.fr/fr/entity/201526866-plateforme-de-microscopie-a-force-atomique-multifonctionnelle-et-interdisciplinaire-imfafm

The proposed PhD topic deals with the study of nanorod hematite photo-anodes, catalytically activated by a “catalyst” layer (M-OOH, with M = Fe, Ni, Co, Cu, Zn) covering a hematite surface for a more efficient production of hydrogen by solar water splitting.



We propose to optimize the photo-electrolysis reaction in an approach that does not oppose energies, but which proposes a mix of energies for the success of an economy based on “low carbon” technologies in a so-called “circular” perspective. Making use of abundant materials, the production, the device regeneration, will be the core of this study.



Hematite nanorods will be deposited by aqueous chemical growth (ACG), a versatile deposition technique suitable for large-scale production. The PhD candidate will be responsible for multiple aspects of the project: (1) the measure and characterization of the photo-electrochemical efficiency using catalytically activated photo-anodes; (2) the study of photo-anodes stability over time; and (3) photo-anodes regeneration in an "active" recycling process. In this respect, the candidate, will have the opportunity to grasp various preparation and characterization techniques: the deposition of photo-anodes by ACG, glassy carbon electrodes nanofabrication, photo-electrochemical characterization, near field microscopy (AFM), X-ray transmission microscopy (STXM), etc. In addition, the thesis student will benefit from an ongoing collaboration between IRAMIS / SPEC and the SOLEIL Synchrotron.
Multiferroic oxynitride thin films for integrated opto-spintronics

SL-DRF-21-0338

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l’Etat Condensé

Laboratoire Nano-Magnétisme et Oxydes

Saclay

Contact :

Antoine BARBIER

Starting date : 01-10-2021

Contact :

Antoine BARBIER
CEA - DRF/IRAMIS/SPEC/LNO

01.69.08.39.23

Thesis supervisor :

Antoine BARBIER
CEA - DRF/IRAMIS/SPEC/LNO

01.69.08.39.23

Personal web page : http://iramis.cea.fr/Pisp/137/antoine.barbier.html

Laboratory link : http://iramis.cea.fr/spec/LNO/

More : https://www.synchrotron-soleil.fr/fr

N-doped oxides and/or oxinitrides constitute a booming class of compounds with a broad spectrum of useable properties and in particular for novel technologies of carbon-free energy production and optoelectronics. The insertion of nitrogen in the crystal lattice of an oxide semiconductor allows in principle to modulate the value of the optical band gap, enabling new functionalities. The production of corresponding single crystalline thin films is highly challenging. In this thesis work, single crystalline N-doped oxides heterostructures will be grown by atomic plasma-assisted molecular beam epitaxy. BaTiO3 will provide ferroelectricity and a favorable absorption spectrum while an additional, eventually N-doped, ferrimagnetic ferrite will give an artificial (opto)multiferroic character. The resulting structures will be investigated with respect to their ferroelectric characteristics as well as their magnetoelectric and optoelectronic couplings, as a function of the N doping. These observations will be correlated with a detailed understanding of crystalline and electronic structures.



The student will acquire skills in ultra-high vacuum techniques, molecular beam epitaxy, magnetometry and photoelectrolysis as well as in state of the art synchrotron radiation techniques.
Bad metal and soft phonons in quantum paraelectric systems

SL-DRF-21-0238

Research field : Solid state physics, surfaces and interfaces
Location :

Laboratoire Léon Brillouin

Groupe 3 Axes

Saclay

Contact :

Philippe Bourges

Starting date : 01-09-2021

Contact :

Philippe Bourges
CEA - DRF/IRAMIS/LLB/NFMQ

0169086831

Thesis supervisor :

Philippe Bourges
CEA - DRF/IRAMIS/LLB/NFMQ

0169086831

Personal web page : http://iramis.cea.fr/Pisp/113/philippe.bourges.html

Laboratory link : http://www-llb.cea.fr/NFMQ/

More : https://www.lpem.espci.fr/spip.php?article72

Doped SrTiO3 is a bad metal where the electrical resistivity does not saturate at high temperature when the mean free path is of the order of interatomic distances. Our recent preliminary results of neutron scattering show that the proximity of the ferroelectric instability, so-called quantum paraelectric phase, play an essential role in the increase of the carriers mass at high temperature (C. Collignon, Ph. Bourges, B. Fauqué and K. Behnia, Phys. Rev. X 10, 031025 (2020)). Further, the tendency towards that structural instability (associated with a soft phonon) is assumed to favor superconductivity in SrTiO3 for dilute doping, even if both types of orders have a priori nothing in common.



Motivated by these results, we propose a PhD research plan to study the effect of electronic doping in quantum paraelectric systems, that will follow two research paths: i) study of the electronic structure via electric and thermoelectric transport measurements ii) study the atomic structure and lattice dynamics by neutron scattering measurements. We will first focus on the doped SrTiO3 compound (substitution with La and Nb, reduction in oxygen) and next to doped compounds of KTaO3 and PbTe. These measurements will allow understanding the nature of the new electronic states of matter that occur in doped quantum paraelectric materials.
Nuclear Magnetic Resonance of tritium: a new tool for understanding tritium speciation in materials of nuclear interest

SL-DRF-21-0267

Research field : Solid state physics, surfaces and interfaces
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Structure et Dynamique par Résonance Magnétique (LCF)

Saclay

Contact :

Thibault CHARPENTIER

Starting date : 01-10-2020

Contact :

Thibault CHARPENTIER
CEA - DRF/IRAMIS/NIMBE/LSDRM

33 1 69 08 23 56

Thesis supervisor :

Thibault CHARPENTIER
CEA - DRF/IRAMIS/NIMBE/LSDRM

33 1 69 08 23 56

Personal web page : http://iramis.cea.fr/Pisp/112/thibault.charpentier.html

Laboratory link : http://iramis.cea.fr/nimbe/lsdrm/

Tritium that is a radioactive isotope of hydrogen is an ubiquitous chemical element in the nuclear industry, both in fission and fusion reactors (ITER) where it is the main fuel. However, tritium, as a a light element, is easily trapped in many materials, resulting in significant quantities of tritiated waste.



The CEA has facilities that are unique in the world for handling tritiated materials and for developing tritium chemistry, for whose it would be interesting to combine with tritium nuclear magnetic resonance (NMR) spectroscopy under high-resolution conditions (rotation of the sample at the magic angle - MAS). The level of sophistication reached by NMR-MAS offers many prospects for a detailed understanding of the mechanisms of tritium incorporation and trapping in many materials of interest to the nuclear industry (metals, plastics, cements, etc.). Helium-3, produced by the decay of tritium, is another isotope that is easily detected by NMR.



The aim of this thesis is to develop and explore the potential of tritium NMR for a wide range of materials currently being studied, in collaboration with the main actors of the CEA’s tritium fields.
Near-field second harmonic generation imaging of magneto-electric chiral antiferromagnets

SL-DRF-21-0432

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l’Etat Condensé

Laboratoire Nano-Magnétisme et Oxydes

Saclay

Contact :

jean-yves Chauleau

Michel VIRET

Starting date : 01-10-2020

Contact :

jean-yves Chauleau
CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 72 17

Thesis supervisor :

Michel VIRET
CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 71 60

Personal web page : http://iramis.cea.fr/spec/Phocea/Membres/Annuaire/index.php?uid=jchaulea

Laboratory link : http://iramis.cea.fr/spec/lno/

The objectives of this PhD are the study of antiferromagnetic topological objects in magneto-electric multiferroïc materials. These ferroelectric/antiferromagnetic textures can be rather challenging to observe, in particular with a required spatial resolution below 100 nm. Second harmonic generation, a non-linear optical approach, has proven to be a powerful and elegant way to image complex multiferroïc textures and to disentangle the different contributions at play. This PhD work will be focused on the use of near-field non-linear optics to unveil the intrinsic mechanisms of the generation and the manipulation of genuine antiferromagnetic skyrmions.
Ab initio simulations of spin polarized STM images

SL-DRF-21-0819

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l’Etat Condensé

Groupe Mésocopie Modélisation et Thermoélectricité

Saclay

Contact :

Yannick DAPPE

Starting date : 01-10-2020

Contact :

Yannick DAPPE
CNRS - DRF/IRAMIS/SPEC/GMT

+33 (0)1 69 08 84 46

Thesis supervisor :

Yannick DAPPE
CNRS - DRF/IRAMIS/SPEC/GMT

+33 (0)1 69 08 84 46

Personal web page : http://iramis.cea.fr/Pisp/yannick.dappe/

Laboratory link : http://iramis.cea.fr/spec/GMT

Since its discovery more than 30 years ago by Binnig and Rohrer [1], the Scanning Tunnelling Microscope (STM) has become a tool of choice, not only for the study of atomic structures of surfaces or surface nanostructures, but also for the determination of the electronic properties of these systems. However, the complexity of the experimentally obtained images frequently requests an advanced theoretical support in order to reach a correct interpretation of the experimental data. In that respect, the determination of the atomic and electronic structure based on Density Functional Theory (DFT) calculations constitutes a very interesting and complementary tool for the characterization of these systems. The purpose of this PhD is to continue further the numerical developments in terms of STM images simulation by taking into account the spin polarization effects. Indeed, the study of magnetic nanostructures is of paramount importance in nowadays research due to the numerous applications in information and communication technologies. In this work, the goal will be to introduce the spin polarization in a DFT code, and then to continue the previously performed developments to determine the spin polarized current between the STM tip and the considered system. These developments will be later compared to reference experimental systems.
Local magnetic microscopy by integration of magnetoresistive sensors

SL-DRF-21-0829

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l’Etat Condensé

Laboratoire Nano-Magnétisme et Oxydes

Saclay

Contact :

Aurélie Solignac

Myriam PANNETIER-LECOEUR

Starting date : 01-10-2020

Contact :

Aurélie Solignac
CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 95 40

Thesis supervisor :

Myriam PANNETIER-LECOEUR
CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 74 10

Personal web page : http://iramis.cea.fr/Pisp/aurelie.solignac/

Laboratory link : http://iramis.cea.fr/spec/LNO/

In order to characterize the local magnetic properties of magnetic materials such as steels, nanoparticles or magnetic rocks, an ultrasensitive and quantitative magnetic microscope has been developed at the Laboratory of Nanomagnetism and Oxides. This microscope combines a local scanning probe microscope of the AFM (Atomic Force Microscope) type and a magnetic sensor integrated in an AFM cantilever. The magnetic sensors used are giant and tunneling magnetoresistance (MR) sensors based on spin electronics and capable of detecting magnetic fields of the order of nT/vHz. The AFM allows monitoring the height of the tip and its displacement, while the MR sensor integrated in the AFM tip measures the magnetic field at each position on the sample.



This innovative tool has so far been applied to the nanometrology of static magnetic fields on a local scale. During this thesis the aim is to investigate other possible applications using a specific property of MR sensors: their wide frequency range in detection from DC to several hundred MHz or even GHz. Thus the magnetic susceptibility properties of unique magnetic nanoparticles can be studied, especially in the context of the use of nanoparticles in biomedical applications for example (biochips, strip tests...). A second targeted application is magnonics or the use of spin waves (rather than charges) to transport and process information with a minimum of energy loss. MR sensors are indeed very good candidates to be miniaturizable detectors of these spin waves and allow their mapping.



In the framework of this thesis, developments will be necessary in order to optimize the response of the sensors according to the targeted application. The performance of the sensors will be studied in terms of magnetoresistance and noise when integrated in flexible cantilever. The thesis will include a clean room microfabrication aspect and a magnetotransport and noise measurement aspect, which will be performed in the shielded magnetic chamber of the Ultra Low Noise platform. The microscope and the sensor detection electronics will also have to be adapted to high frequency measurements in order to exploit the potential of the microscope for innovative applications.

Structure and Spectroscopic Properties of Oxyde Materials with Machine Learning

SL-DRF-21-0544

Research field : Solid state physics, surfaces and interfaces
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Structure et Dynamique par Résonance Magnétique (LCF)

Saclay

Contact :

Thibault CHARPENTIER

Starting date : 01-10-2021

Contact :

Thibault CHARPENTIER
CEA - DRF/IRAMIS/NIMBE/LSDRM

33 1 69 08 23 56

Thesis supervisor :

Thibault CHARPENTIER
CEA - DRF/IRAMIS/NIMBE/LSDRM

33 1 69 08 23 56

Personal web page : http://iramis.cea.fr/Pisp/thibault.charpentier/

Laboratory link : http://iramis.cea.fr/nimbe/lsdrm/

This thesis aims to developing Machine Learning approaches for modelling structural and spectroscopic (NMR and RAMAN) of oxides materials (ceramics, borosilicate glasses and simplified nuclear waste glasses) et their interactions with water. NMR, Raman and oxide/H2O interactions can be simulated with DFT methods but are limited to system sizes of few hundreds of atoms and for trajectory less than ~100 ps. Parametrization of sophisticated classical force fields (polarizable, aspherical ions) is a complex task and transferability to large domain of composition is limited. Similarly, NMR and Raman spectra can be simulated with parametric approaches but only for very simple glasses. Additionally, there are no known classical force-fields capable fof modelling interactions of water with aluminoborosilicate glasses with a DFT accuracy.



To overcome these limitations while keeping the accuracy and transferability of DFT methods, Machine Learning methods (which are parameter-free approaches) have recently emerged and are very promising. In this thesis, ML and hybrid (i.e. coupled with Classical methods) force-fields will be developed for modelling oxides glasses, their NMR and Raman spectra (for comparison with experiments), and glass/water interactions for feeding Monte-Carlo simulations of long-term glass alterations.
Fragmentation in frustrated magnets

SL-DRF-21-0381

Research field : Solid state physics, surfaces and interfaces
Location :

Laboratoire Léon Brillouin

Groupe 3 Axes

Saclay

Contact :

SYLVAIN PETIT

Starting date : 01-10-2021

Contact :

SYLVAIN PETIT
CEA - DRF/IRAMIS/LLB

01 69 08 60 39

Thesis supervisor :

SYLVAIN PETIT
CEA - DRF/IRAMIS/LLB

01 69 08 60 39

Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=spetit

Laboratory link : http://iramis.cea.fr/llb/nfmq/

In recent years, the study of spin liquids has aroused great interest in condensed matter physics. These new quantum states of matter are indeed described using emerging gauge fields and exhibit large-scale quantum entanglement. The spin ice state, for example, does not show any symmetry breaking, but is nevertheless locally organized. The rule that describes this organization is a law of local conservation and is interpreted as an emergent gauge field.



Here we seek to describe situations where defects to this rule appear, that is, in the language of the gauge field, "charges", also called monopoles. These descriptions are based on a Helmholtz decomposition of the field, hence the term magnetic "fragmentation".



This project proposes a numerical approach to the problem, using a direct simulation of the equations of motion, taking into account the source terms of these monopoles. These simulations are also based on Monte-Carlo sampling of the phase space, a complex work in the context of so-called frustrated systems such as spin ice. The challenge is therefore to develop a numerical tool, as close as possible to the experiments and to propose an interpretation in terms of fragmentation. These simulations must also be predictive, in order to draw up a portrait of the phases in presence as well as their excitation spectra.

Ultrafast pure spin current transport through antiferromagnetic insulators

SL-DRF-21-0431

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l’Etat Condensé

Laboratoire Nano-Magnétisme et Oxydes

Saclay

Contact :

jean-yves Chauleau

Jean-Baptiste MOUSSY

Starting date : 01-11-2020

Contact :

jean-yves Chauleau
CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 72 17

Thesis supervisor :

Jean-Baptiste MOUSSY
CEA - DRF/IRAMIS

01-69-08-72-17

Personal web page : http://iramis.cea.fr/spec/Phocea/Membres/Annuaire/index.php?uid=jchaulea

Laboratory link : http://iramis.cea.fr/spec/lno/

Pure spin-currents are playing a major role in modern spintronics. Mastering their ultrafast and efficient transport allows to extend spintronics concepts to the terahertz range. The main objective of this PhD is to address the underlying mechanisms of the dynamics of spin-current transport through antiferromagnetic insulators. These materials are now attracting a substantial interest mainly due to their ultrafast capabilities. We propose here to explore the different characteristics of the terahertz pure spin-current transport in antiferromagnets using time-resolved optical techniques (magneto-optics and second harmonic generation) and terahertz spectroscopy.
Interface electronic and chemical structure of voltage tunable ferroelectric capacitors for 5G applications

SL-DRF-21-0949

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l’Etat Condensé

Laboratoire d’Etude des NanoStructures et Imagerie de Surface

Saclay

Contact :

Nick Barrett

Starting date : 01-10-2021

Contact :

Nick Barrett
CEA - DRF/IRAMIS/SPEC/LENSIS

0169083272

Thesis supervisor :

Nick Barrett
CEA - DRF/IRAMIS/SPEC/LENSIS

0169083272

Personal web page : http://iramis.cea.fr/Pisp/nick.barrett/

Laboratory link : http://iramis.cea.fr/spec/Phocea/Vie_des_labos/Ast/ast_visu.php?id_ast=2075

The PhD thesis is an experimental study of the interface chemistry and electronic structure of BaSrTiO3 based capacitors for 5G and NFC applications. Using a unique sample preparation method, the combinatorial PLD available at the GREMAN laboratory in Tours, the student will carry out high resolution mapping of the band line-ups at the top and bottom interfaces of these prototypical voltage tunable capacitors (varactors). Results will be compared with electrical characteristics obtained at ST Microelectronics (Tours) and with first principles DFT based calculations done at CEMES. Finally, chosen sample interfaces will be studied in operando conditions using HAXPES to determine the response of the electronic structure and therefore key parameters such as the SBH, to applied bias in real working conditions. A high level of mobility is required of the PhD student with working visits to partner laboratories (GREMAN-Tours, ST Tours and CEMES-Toulouse) and participation in synchrotron beamtime measurements.
Attosecond quantum electronics in semiconductors

SL-DRF-21-0455

Research field : Solid state physics, surfaces and interfaces
Location :

Service Laboratoire Interactions, Dynamique et Lasers

Attophysique (ATTO)

Saclay

Contact :

Willem Boutu

Hamed MERDJI

Starting date : 01-09-2021

Contact :

Willem Boutu
CEA - DRF/IRAMIS/LIDYL/ATTO

0169085163

Thesis supervisor :

Hamed MERDJI
CEA - DRF/IRAMIS/LIDyL/ATTO

0169085163

Personal web page : http://iramis.cea.fr/LIDYL/Phocea/Page/index.php?id=99

Laboratory link : http://iramis.cea.fr/LIDYL/Phocea/Page/index.php?id=99

Today, gigahertz electronics are under control and the terahertz regime is barely accessible. Quantum technologies must now anticipate recent advances in Moore's law evolutions but in the quantum field. Indeed, thanks to the innovative technologies offered by femtosecond lasers, electronic components will progress towards the petahertz range, which involves controlling electronic dynamics at the attosecond scale. The candidate will study in dielectrics and semiconductors the ultra-fast and high mobility properties of electrons when exposed to intense femtosecond laser fields. We will study how the strong current of electrons can be controlled at petahertz frequencies in the conduction band, by the laser field. In addition to these temporal aspects, it has been shown theoretically that these lasers can transfer spin or angular momentum, thus making it possible to shape the quantum state of the system. The thesis will focus on applications in quantum information by topology on 2D semiconductors.
Spin ice coupled to a phonon bath

SL-DRF-21-0382

Research field : Solid state physics, surfaces and interfaces
Location :

Laboratoire Léon Brillouin

Groupe 3 Axes

Saclay

Contact :

SYLVAIN PETIT

Starting date :

Contact :

SYLVAIN PETIT
CEA - DRF/IRAMIS/LLB

01 69 08 60 39

Thesis supervisor :

SYLVAIN PETIT
CEA - DRF/IRAMIS/LLB

01 69 08 60 39

Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=spetit

Laboratory link : http://iramis.cea.fr/llb/nfmq/

In recent years, the study of spin liquids has aroused great interest in condensed matter physics. These new quantum states of matter are indeed described using emerging gauge fields and exhibit large-scale quantum entanglement. The spin ice state, for example, does not present any symmetry breaking, but is nevertheless locally organized. The rule that describes this organization is a local conservation law and is interpreted as an emergent gauge field.



Here we seek to describe situations where, through magneto-elastic coupling, zero-point movements of atoms induce magnetic fluctuations. As a result, the gauge field fluctuates over time, giving rise to an electric field in addition to the magnetic field. This new phase is called quantum spin ice.



This project proposes a numerical approach to the problem, using a direct simulation of the equations of motion, taking into account a random force that can cause the spin state to change locally and thus induce these fluctuations. These simulations are also based on Monte-Carlo sampling of the phase space, a complex work in the context of so-called frustrated systems such as spin ice. The challenge is to develop a numerical tool capable of predicting the stability of the phases, to propose an interpretation in terms of emerging fields and to characterize the excitation spectrum. We will strive to stay as close as possible to the experiments carried out in the laboratory, on model systems (pyrochlore and rare earth garnets) where it is believed that these fluctuations are at work.
Biophysical approach for the structural study of the TSPO membrane protein

SL-DRF-21-0933

Research field : Structural biology
Location :

Laboratoire Léon Brillouin

Groupe Biologie et Systèmes Désordonnés

Saclay

Contact :

Sophie COMBET-JEANCENEL

Starting date : 01-10-2021

Contact :

Sophie COMBET-JEANCENEL
CNRS - GBSD/Groupe Biologie et Systèmes Désordonnés

0169086720

Thesis supervisor :

Sophie COMBET-JEANCENEL
CNRS - GBSD/Groupe Biologie et Systèmes Désordonnés

0169086720

Personal web page : http://iramis.cea.fr/Pisp/sophie.combet/

Laboratory link : http://www-llb.cea.fr/index.php

More : http://www.labos.upmc.fr/lbm/recherche.html

We are interested in the membrane transporter TSPO, a ubiquitous and functionally important 18 kDa protein used as a marker in many brain diseases in humans. So far, no crystals have been obtained for mammalian TSPOs. Therefore, obtaining a high resolution structure of these proteins by X-ray crystallography remains a challenge. We propose, in this PhD project, to determine the optimal stabilization conditions of mTSPO (mouse) and hTSPO (human) without ligand, with the aim of their crystallization. We will characterize the solution structure of TSPO/surfactants and TSPO/lipids/surfactants complexes by coupling radiation scattering data (MALLS, SANS, and SAXS) with ab initio simulations. We will first target SDS (the anionic detergent used in the extraction and purification of mTSPO) and DPC (the zwitterionic detergent used to obtain the NMR structure of mTSPO in the presence of a stabilizing ligand). We will then study TSPO/DMPC/DPC ternary mixtures, a biomimetic environment close to the conditions allowing the binding of ligands with high affinity, to determine the first steps of TSPO crystallization.
Modelling and simulation of the self-assembly of nanoparticles under an external magnetic field

SL-DRF-21-0790

Research field : Ultra-divided matter, Physical sciences for materials
Location :

Laboratoire des Solides Irradiés

Laboratoire des Solides Irradiés

Saclay

Contact :

Marc HAYOUN

Starting date : 01-10-2021

Contact :

Marc HAYOUN
CEA - DRF/IRAMIS/LSI

0169334533

Thesis supervisor :

Marc HAYOUN
CEA - DRF/IRAMIS/LSI

0169334533

Laboratory link : https://portail.polytechnique.edu/lsi/fr/recherche/physique-et-chimie-des-nano-objets

The incorporation of nanoparticles (NPs) in a polymer matrix and their exposure to particular conditions can lead to a process of self-assembly, going from a disordered state to organized structures and patterns. The self-assembly process of magnetic NPs is associated with interactions between dipoles which tend to spontaneously align along the lines of the external magnetic field. Controlling the formation of these nanochains is crucial to take advantage of their properties. Due to the complexity of these systems, no rigorous model exists to fully describe them. The first stage of the thesis will be devoted to the development of a specific molecular dynamics code based on a model describing the interactions of paramagnetic NPs with a magnetic field. The goal will be to account for the generic behaviour of this type of systems. The second step of the thesis will be to extend the code and the interaction model to the case of ferromagnetic NPs. The third step will guide the laboratory experiments by performing numerical simulations in order to predict the behaviour of these NPs under different conditions.
Synthesis of nanoparticles automated by SAXS measurement: elaboration of feedback via a numerical model of nucleation / growth

SL-DRF-21-0441

Research field : Ultra-divided matter, Physical sciences for materials
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Interdisciplinaire sur l’Organisation Nanométrique et Supramoléculaire

Saclay

Contact :

Olivier TACHE

David CARRIÈRE

Starting date : 01-10-2021

Contact :

Olivier TACHE
CEA - DRF/IRAMIS/NIMBE/LIONS


Thesis supervisor :

David CARRIÈRE
CEA - DRF/IRAMIS/NIMBE/LIONS

0169085489

Personal web page : http://iramis.cea.fr/Pisp/david.carriere/

Laboratory link : http://iramis.cea.fr/nimbe/lions/

More : http://iramis.cea.fr/Pisp/olivier.tache/

The small size of nanoparticles gives them exceptional properties that are interesting for a wide range of applications in optics, energy production and storage, and medicine, to name but a few. Very often, such applications in turn require a very fine control of the size, structure and state of aggregation of the nanoparticles. However, currently, this control is only approximate and relies primarily on trial and error approaches.



In this context, we are developing an innovative approach to master the final nanoparticles by designing an automated synthesis setup, with a feedback loop between the size, number and state of aggregation of nanoparticles measured in real time by small-angle ray scattering (SAXS), and the operational parameters of the synthesis (flow of reactants, pH, temperature).



The precise objectives of this thesis are 1) to develop the real-time comparison of SAXS models with physical models, and evaluate the added value of Machine Learning, 2) to understand the dependence of nucleation, growth and aggregation rates on operational parameters both by using the current theories and by analyzing numerically the correlations between inputs and outputs, and 3) use this fundamental understanding to build the feedback loop. The approach will be tested first on simple model syntheses (SiO2), where a size control better than one nanometer is expected.
Hybrid imogolites as tunable nanoreactors

SL-DRF-21-0430

Research field : Ultra-divided matter, Physical sciences for materials
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Interdisciplinaire sur l’Organisation Nanométrique et Supramoléculaire

Saclay

Contact :

Antoine THILL

Starting date : 01-11-2021

Contact :

Antoine THILL
CEA - DRF/IRAMIS/NIMBE/LIONS

01 69 08 99 82

Thesis supervisor :

Antoine THILL
CEA - DRF/IRAMIS/NIMBE/LIONS

01 69 08 99 82

Personal web page : http://iramis.cea.fr/Pisp/antoine.thill/thill_fr.html

Laboratory link : http://iramis.cea.fr/Pisp/LIONS/

Reconciling human development and environment preservation is one of the most difficult problem researchers will face in the coming years. This will be all the more difficult with the need to shift from fossil fuel use to renewable energies such as solar energy, find alternatives for rare elements and manage resources in a more sustainable way. In this project, we propose to explore the photocatalytic properties of low price and environmental-friendly alumino-silicate nanotubes, i.e. imogolites, to trigger unfavorable redox reactions on both sides of the hybrid imogolite wall, taking advantage of confinement inside the cavity and of the polarization of the wall. A specificity, and the originality, of this project is that under confinement in a nano-reactor, the majority of the molecules are under the influence of structurally controlled interactions that can modify chemical reactions in a way inaccessible in the bulk phase. The project will in particular try to evaluate the role of the curvature-induced polarization for the separation of charge through the wall of imogolites and to control interfaces and interactions at the nanometer scale to obtain original properties.



Coupling hydrophilic/hydrophobic redox reactions in a nano-reactor is unique and the development of the hybrid materials presented may open an avenue of new possible photo-induced reactions. The realization of this project is expected to have a very strong impact not only on the understanding of reactivity in confined systems, as well as in the field of photocatalysis for environmental and energy applications.
Capture of atmospheric CO2 with nanofluids

SL-DRF-21-0451

Research field : Ultra-divided matter, Physical sciences for materials
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Interdisciplinaire sur l’Organisation Nanométrique et Supramoléculaire

Saclay

Contact :

Christophe FAJOLLES

David CARRIÈRE

Starting date : 01-10-2021

Contact :

Christophe FAJOLLES
CEA - DSM/IRAMIS/NIMBE/LIONS

01 69 08 99 60

Thesis supervisor :

David CARRIÈRE
CEA - DRF/IRAMIS/NIMBE/LIONS

0169085489

Personal web page : http://iramis.cea.fr/Pisp/david.carriere/

Laboratory link : http://iramis.cea.fr/nimbe/lions/

One of the ways strongly encouraged by the IPCC (Intergovernmental Panel on Climate Change) to mitigate climate change is the capture of CO2 by liquid amines, followed by the recovery of the gas and its deep underground storage. However, an essential problem makes the process currently inefficient: the recovery of CO2 must be done by heating and is too energy intensive.



In this context, this thesis will study how the addition of nanoparticles improves the recovery of CO2 from liquid amines. These “nanofluids” have proven efficacy, but there is little guidance on how to achieve an appropriate composition, and no consensus on the mechanism that would facilitate the release of CO2 gas.



The objective of this thesis is to propose rational guidelines, which will lead to the best nanoparticle + liquid amine combination, replacing the current trial-and-error approaches. It will therefore be necessary to study how the surface of nanoparticles 1) activates the chemical reaction of release, and 2) facilitates the physical process of nucleation of gas bubbles.

 

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