News
| Jul 2025 |
ArXiv release of our observation of entanglement in a cold atom analog of preheating!We have released a new observation on arXiv . In it, we excite parametrically collective excitations  in a Bose-Einstein condensate, which mimics parametric amplification of particle in preheating, the stage after cosmic inflation  . This is done by changing periodically the effective 1D coupling constant of the elongated cloud, which parametrically produce pairwise opposite momentum quasiparticles  . As the initial temperature of the gas is very low, the exponential growth of the excitation number is largely triggered by vacuum fluctuations, resulting in an entangled state, which we observe  . Have a look at it!
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| Jun 2025 |
Our pulse shaping paper is published in Phys. Rev. A!
 ! I summarize the key results in this post but to have all the detail, you should have a look at it  .
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| May 2025 |
Invited seminar at HeidelbergI’ve just returned from Heidelberg University  , where I had the pleasure of visiting Prof. Markus Oberthaler and his fantastic team for two days. It was a great opportunity to present my PhD work and to discuss future research directions and collaborations  . A heartfelt thank you to everyone for the warm welcome and inspiring discussions  !
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| Mar 2025 |
Contributed talk in Nottingham
I attended the Quantum Simulation for Fundamental Physics conference in Nottingham, Robin’s Hood city  . I had the opportunity to present  our recent theoretical work on how to probe entanglement of Gaussian states based on their full counting statistics (slides here). Thanks a lot the organizers for the very nice organization  !
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| Mar 2025 |
New preprint on ArXiv - Entanglement of two-mode bosonic Gaussian states
Our new preprint is available on the ArXiv  ! We study the entanglement properties of two-mode bosonic Gaussian states from their multi-mode counting statistics, i.e. simply counting particles. In particular, we show that the  - and  -body number correlations are sufficient to fully characterize the entanglement of two-mode bosonic Gaussian states for which each mode exhibits a thermal distribution. In addition, we derive an entanglement witness based on two-body correlations alone. Our findings reveal entanglement in a series of recent experiments  . Further details are given in a related post.
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| Feb 2025 |
Publication of my PhD thesis
My PhD manuscript has been officially released
 . The HTML preprint can be accessed here or the pdf is accessible via this link .
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| Jan 2025 |
Doctor of Université Paris-Saclay!
I successfully defended my PhD today   ! A warm thank you to all the members of my jury for taking the time to read my work and for the interesting discussion we had. Another heartfelt thanks to everyone who contributed to cooking for the pot  and, more generally, to making this day soooo nice   ! If you missed the presentation, the slides are here, but be aware that the GIF will sadly not work  …
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| Jan 2025 |
Seminar on entanglementI presented a new theoretical result which explains how we can quantify entanglement of two-mode bosonic Gaussian states from their full counting statistics i.e. by counting the number of individual particles in each mode . The slides are available here or further details are given in a related post. Stay tuned for the upcoming paper !
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| Nov 2024 |
Preprint of our Pulse shaping paper
Our new paper titled “Coherent coupling of momentum states: selectivity and phase control” is available on ArXiv  !
In particular, we compare different Bragg deflector and propose a new scheme to implement a robust four-mode interferometer.
See the related post for more information  .
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| Oct 2024 |
French Quantum Gases workshop @Toulouse
The French Quantum Gases community gathered for a three days meeting in Toulouse
 . It was the opportunity to present our new theoretical work  on the measurement of entanglement of bi-partite Gaussian states with 2- and 4-body correlation functions  .
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| Jul 2024 |
ICAP @LondonI presented a poster on Tuesday at the ICAP conference, in the Imperial College (London ). Do not hesitate to have a look  !
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| Jun 2024 |
New doctor in the team
Charlie successfully defended his PhD today – congratulations   ! Do not hesitate to have a look to his manuscript: you will find many wonderful interference patterns. His work focuses on the shaping and optimization of Bragg pulses to perform an atomic interferometer.
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| Apr 2024 |
Inscription and submission to PhDay Conference @Saclay are opened
Together with Géraud Dupuis and David Theidel, we organize a conference that aims to connect Saclay students (Master, PhD, PostDoc) of quantum related subjects and provide them a nice opportunity to present the research project they are involved in. Inscription and contributions are opened.
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| Feb 2024 |
Our paper on sub-shot noise interferometry was published in Phys. Rev. A ! We have just published  a new article focusing on sub-shot-noise interferometry with two-mode quantum states. In this paper, we compare the advantage of different input state - twin-fock or two-modes squeezed state - when taking into account the losses due to the finite efficiency of the detector. We also provided our analytical formulas in a python package qsipy, making possible for experimentalists to check the sensitivity of their interferometer depending on the input state and detector properties. The PDF version with the supplemental material can be downloaded
here .
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| Nov 2023 |
Talk @LKB in ParisA meeting was organized by the analog gravity community to discuss the topic of analog cosmology. The goal of this meeting was to gauge the level of interest in a “Transverse Task Force” of the GDR COPHY. My slides are available here. |
| Oct 2023 |
Some changes in the team !
The Quantum Atom Optics team has undergone some changes: Clothilde just arrived to start her PhD, while Quentin left us to work at ONERA. Paul joined our team for a 6-month internship before returning to LCF to work on the other helium experiment . Of course, Charlie, Denis, and Chris are still here!
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| Sep 2023 |
Amaury's PhD defenseAmaury just got his PhD, congrats ! He will stay in Institut d’Optique for two months before mooving to Japan, at the Riken institute.
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| Jun 2023 |
Analog Gravity Summer SchoolI just come from the Benasque Analog Gravity Summer School & workshop  . The first week of the stay was the summer school, aiming to train the new generation of researchers. The second week brought together an expanding community of experimental and theoretical physicists who shared their work, with very nice presentation and discussions. Quentin presented our latest advances, and I presented a poster. A heartfelt  thank you to the organizers for facilitating such enriching experiences!
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| Mar 2023 |
Laboratory Charles Fabry scientific days
This Monday, March 27th, the scientific day of the Charles Fabry laboratory took place, which I co-organized. I also presented the actions of the 'Ecology' working group of the laboratory, including the Carbon Footprint calculation method implemented by Lab 1.5.
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| Jan 2023 |
Talk @LCFI presented today my PhD subject during an hour to the people from the laboratory (Laboratoire Charles Fabry). The slides can be downloaded here. |
| Dec 2022 |
Theoretical result by Amaury & Scott
Amaury and Scott just published a paper in the last 2022 issue of Physical Review B, where they study Phonon decay in one-dimensional atomic Bose quasicondensates via Beliaev-Landau damping. Especially, using the Fermi golden rule, they derive a simple analytic formula for the decay rate of the phonon occupation number. Their result can explain why the 2012 experiment did not witness entanglement. Do not hesitate to have a look!
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| Dec 2022 |
New doctor in the team
Quentin successfully earned his PhD today – congratulations
! Do not hesitate to have a look to his manuscript. His thesis defense gathered the last five PhD students who contributed to the experiment, encompassing the doctoral candidates from 2016 to 2024.
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| Oct 2022 |
Fête de la science
This weekend, the Institut d'Optique welcomed visitors as part of the Fête de la Science. We were able to introduce the general public to our experiments on cold atoms, popularize our research work, and explain the basic principles of laser cooling. The poster we presented can be downloaded as a
pdf or svg.
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| Jul 2022 |
Talk @SFO in NiceI presented today the preliminary result we just got on the COSQUA project at the French Optical Society congress in Nice. The presentation slides can be downloaded here. |
| Sep 2021 |
From the 1st to the 2nd quantum revolution Summer Scool @PeyresqI just come from Peyresq, a wonderfull little village in the Alpes, were I was for a one week summer school on quantum physics, non-locality and quantum information. Many thanks to the organizers ! |
| Jun 2021 |
PhD scholarship awardI just got a grant to realize my PhD under the supervision of Chris Westbrook and Denis Boiron in the Quantum Atom Optics team, at Institut d’Optique Graduate School. My grant comes from the Quantum Paris-Saclay program and the Ile-de-France region under the SIRTEQ program .
Group picture of the Quantum Atom Optics team I join for the next 3 years. From left to right, Marc, Alex, and Denis are standing up, while Charlie, Quentin, and Chris are sitting down.
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