Myriam PANNETIER-LECOEUR

– ADAGE – Augmented Magnetic Sensing (coordination);  PEPR SPIN (2023-2029)

The rapid development of our digital world is creating strong demand for magnetic sensing. The aim of the ADAGE Targeted Project is to develop more sensitive, energy-efficient, agile and versatile sensors by combining an in-depth understanding of nanomagnetism, improved nanofabrication, new materials and electronic architectures for a new generation of spintronic sensors with enhanced functionality.
– 9 partners.

– STORM – Spin Orbit TOrque Magnetic sensing (coordination) – funded by ANR (2022-2025)

Spintronics offers many advantages for magnetic detection: sensitivity, small size and CMOS integrability. It is therefore already industrialized for many applications, including automotive, cell phones… In the STORM project, the main objective will be to develop a new generation of smart spintronic sensors based on TMR using reconfigurable magnetic layers. Customized tuning will be achieved by the action of spin-orbit coupling induced torques of the appropriate materials, allowing manipulation of the magnetization in specifically designed sensor stacking. This will result in a novel class of smart magnetic sensors, which will be addressable and tunable throughout the sensor’s lifetime, allowing to suppress offset drift, reduce noise, adjust range, operate in a closed loop… The consortium includes two academic partners and one SME with complementary expertises from fundamentals in spin-orbitronics to sensor design and testing for commercialization.

In collaboration with Laboratoire Albert Fert and Spin-Ion Technologies

– TiReDHel – Time Resolved Dynamics of Helical Edge States (partner, coordinated by M. Ferrier-LPS) – funded by ANR (2023-2028)

One of the most promising features of topological matter is the presence of helical ballistic edge states, pure one-dimensional propagating electronic states protected from backscattering by spin-momentum locking. When coupled to superconducting electrodes, a supercurrent is carried by topological Andreev bound states (ABS) also presenting spin-momentum locking. However, we are still far from a complete understanding of the role of the spin degree of freedom and the parity conservation. A major issue is to find unambiguous experimental signatures of the topological protection. We propose to tackle this problem through measurements of the dynamics and relaxation mechanisms of such states, which is still poorly explored experimentally.

Our general idea is to develop an ultrasensitive magnetic field sensor by combining cryogenic amplifiers adapted to giant magneto-resistive (GMR) sensors, both homemade. We plan to detect fluctuations of the supercurrent at equilibrium in topological material coupled to superconducting electrodes. These current fluctuations originate from thermal excitation of ABS on a time scale given by the inelastic relaxation time, which can be as large as few milliseconds. This makes possible the real time detection of supercurrent fluctuations.
We thus propose to improve the bandwidth and sensitivity of GMR detector up to the MHz range in order to detect real time fluctuations of occupation of the topological ABS. We will use different topological materials (Bi nanowires, WTe2 and Bi4Br4) whose fabrication we master and on which we have evidenced edge states.

Eventually, such a high sensitivity should allow us to detect persistent current created by 1D loops of helical edge states in topological systems without superconducting contacts. This would represent one of the most relevant and direct evidence of the topological states.

Magnetic Sensors,
Pannetier-Lecoeur, M., Fermon, C. In: Coey, J.M.D., Parkin, S.S. (eds) Handbook of Magnetism and Magnetic Materials. Springer (2021).

Spin electronics for biomagnetism and Nuclear Magnetic Resonance
Myriam Pannetier Lecoeur, Reina Ayde, Claude Fermon
in Nanomagnetism: Applications and Perspectives, First Edition. Edited by Claude Fermon.
2017 Wiley-VCH Verlag GmbH & Co. KGaA. Published 2017

Spin electronics based magnetic sensors for biomagnetic measurements
M. Pannetier-Lecoeur, C. Fermon, P. Campiglio, Q. Herreros, G. Jasmin-Lebras.
In Magnetoencephalography, From Signals to Dynamic Cortical Networks, Supek, Selma; Aine, Cheryl J. (Eds.)

Noise in GMR and TMR sensors, C. Fermon and M. Pannetier-Lecoeur
In Giant Magnetoresistance (GMR) sensors, from Basis to State-of-the-Art applications, Editors: C. Reig, S. Cardoso de Freitas, S. C; Mukhopadhay, Springer (2013)