Non-Gaussian quantum resources (M/F)

Job Description

Missions

A Postdoctoral / Research Engineer position is open at the Laboratoire Kastler Brossel (LKB), within the Multimode Quantum Optics group, to work on the implementation of quantum computing protocols using non-Gaussian states of light. This position is part of a technology transfer project whose results are intended to be valorized in the long term through our future spin-off.

Activity

The main activity will consist of developing quantum information protocols (distillation, purification, breeding, etc.) to overcome the limited quality of non-Gaussian states currently available in laboratories. This will require an in-depth study of the state of the art to identify the most promising approaches for implementation on our experimental platforms. The position is theoretical in nature and involves close collaboration with the experimental teams participating in the technology transfer project.

This position offers the opportunity to bring a fresh perspective to well-established protocols (measurement-based quantum computing, quantum error-correcting codes, etc.) using algebraic and geometric techniques based on the stellar representation, which have been developed in recent years to study quantum states of light [1,2].

The project is embedded within the Multimode Quantum Optics group at LKB, which conducts leading research on the experimental generation of squeezed states and continuous-variable entangled states for the implementation of quantum information protocols. Activities in this field range from the generation of large entangled networks multiplexed both in time and frequency [3,4,5], to the implementation and certification of non-Gaussian operations in fully optical setups [6,7], as well as the development of tailored continuous-variable quantum optical resources for light–matter interactions [8].

[1] A. Aralov, É. Gillet, V. Nguyen, A. Cosentino, M. Walschaers, M. Frigerio, "Photon catalysis for general multimode multi-photon quantum state preparation", arXiv:2507.19397 (accepted in PRX Quantum)
[2] C. E. Lopetegui-Gonzalez, M. Frigerio, M. Walschaers, "Geometric characterization of non-Gaussian entanglement for finite stellar rank states", arXiv:2511.02076
[3] V. Roman-Rodriguez, D. Fainsin, G.L. Zanin, N. Treps, E. Diamanti, V. Parigi Multimode squeezed state for reconfigurable quantum networks at telecommunication wavelengths Physical Review Research 6 (4), 043113 (2024)
[4] T. Kouadou, F. Sansavini, M. Ansquer, J. Henaff, N. Treps, V. Parigi Spectrally shaped and pulse-by-pulse multiplexed multimode squeezed states of light APL Photonics 8 (2023)
[5] Y. Cai, J. Roslund, G. Ferrini, F. Arzani, X. Xu, C. Fabre, N. Treps Multimode entanglement in reconfigurable graph states using optical frequency combs Nature communications 8 (1), 15645 (2017)
[6] YS Ra, A Dufour, M Walschaers, C Jacquard, T Michel, C Fabre, N Treps Non-Gaussian quantum states of a multimode light fieldNature Physics 16 (2), 144-147 (2020)
[7] U. Chabaud, G. Roeland, M. Walschaers, F. Grosshans, V. Parigi, D. Markham, N. Treps Certification of non-Gaussian states with operational measurements PRX Quantum 2 (2), 020333 (2021)
[8] M. Moreno-Cardoner, D. Goncalves and D. E. Chang Quantum Nonlinear Optics Based on Two-Dimensional Rydberg Atom Arrays Phys. Rev. Lett. 127, 263602 (2021)

Your Profil

Skills

Candidates must hold an internationally recognized PhD in a field related to experimental quantum physics. A good background and past research track record in quantum optics, and/or theory of quantum computing is required. Knowledge about non-gaussian states and continuous variables systems is a plus.

Your Work Environment

As a whole, the group has a tradition of working together with a diverse range of people from varied backgrounds. This diversity often leads to fruitful scientific input from different points of view, and it allows the group to explore new avenues. Furthermore, the moderate size of our group gives PhD students and postdocs the opportunity to discuss with PIs on a daily basis. This gives rise to a dynamical atmosphere with a lot of space for discussion. Laboratoire Kastler Brossel is one of the main worldwide leaders in the field of fundamental physics of quantum systems, covering a number of subjects spanning from fundamental tests of quantum theory to applications. It has an internationally recognized expertise throughout its 65 years history, including three Nobel Prize winners. The multimode quantum optics team explore both fundamental science and applications in CV quantum information. Based in Sorbonne Université in the Pierre and Marie Curie Campus in the center of Paris, it is part of the Quantum Information Center (QICS) in Sorbonne, hosting both quantum physicists and computer scientists. It is also part of the Paris Centre for Quantum Technologies (PCQT), a research, training and innovation network involving 22 research laboratories in Paris Region, 35 start-ups and larger industry groups.

Compensation and benefits

Compensation

Between 2 847,42 € and 3 620,32 € Gross

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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