Angle-resolved quantum state tomography of photoemission at the attosecond timescale

Full description

Attosecond pulses (1 as = 10⁻¹⁸ s) make it possible to investigate electron dynamics on extremely short timescales. Using these pulses, scientists can probe the dynamics of photoemission, the process by which an electron is ejected from an atom by interaction with light [1]. But how can we characterize the quantum state of the emitted electron? And can we go further and understand how quantum coherence and entanglement evolve during this process?

Traditionally, the interpretation of attosecond experiments has relied on describing the photoelectron as a pure quantum state, in which the phase relationships between its different components are well defined. However, during photoemission, the electron can become entangled with other elements, such as the residual ion left behind. This entanglement can affect the quantum coherence of the photoelectron, calling for new methods to characterize its quantum state. To achieve this, two quantum-state tomography techniques have recently been developed to reconstruct the quantum state of these electrons and investigate the effects of entanglement [2,3].

So far, these methods have been implemented using measurements that do not distinguish between different electron emission directions. Yet, this angular information could reveal important features of the photoelectron quantum state. The aim of this internship is therefore to develop the experimental tools needed to reconstruct photoelectron quantum states while taking their emission direction into account. To this end, the student will work with a velocity-map imaging spectrometer, which makes it possible to measure both the angular distribution and the energy of emitted electrons [4].

The internship will be divided into two stages. First, the student will contribute to commissioning and characterizing the velocity-map imaging spectrometer in preparation for attosecond spectroscopy experiments. They will then take part in experiments on photoemission from gas-phase atoms, with the aim of reconstructing the photoelectron quantum state including the information on its emission direction and retrieve the entanglement dynamics at the attosecond timescale.

The internship will take place at the Astérix beamline of the ATTOLab laser facility at CEA Paris-Saclay. The student will receive training in attosecond physics, ultrafast optics, and atomic and molecular physics. They will also gain hands-on experience with vacuum systems and charged-particle detection.

This internship offers the opportunity to contribute to a research project at the interface of attosecond science and quantum physics, in a state-of-the-art experimental environment. The project may be continued as part of a PhD, allowing the student to further develop these methods and apply them to the study of electron quantum dynamics.

[1] A. Autuori, et al., Science Advances 8, eabl7594 (2022)
[2] C. Bourassin-Bouchet, et al., Phys. Rev. X 10, 031048 (2020)
[3] H. Laurell, et al., Nature Photonics 19, 352–357 (2025)
[4] M. J. J. Vrakking, Phys. Chem. Chem. Phys. 16 (7), 2775–2789 (2014)

Location

France

Internship conditions

• Internship duration: 6 months
• Level of study: Bac+5
• Training: Master 2
• Continuation in PhD thesis: Yes
• Application deadline: 26 octobre 2026

Supervisor

Gabriele CRIPPA
Phone: +33 1 69 08 17 55
Email :

Head of the laboratory LIDYL / ATTO

Phone: