Victor Gondret

I am a post-doctoral researcher working in experimental quantum physics. I did my PhD work on collective excitations in a metastable helium Bose-Einstein condensate, in Paris-Saclay University . During my PhD, I introduced a novel entanglement criterion which allowed observing entanglement between parametrically driven collective excitations in the quantum fluid. More details on my work can be found in the Research page.

Since October 2025, I have been working at the Amazing Quantum laboratory, led by Carla Hermann at the University of Chile in Santiago . The lab specializes in quantum optics and was inaugurated last January. The project I am currently involved in aims to study and generate intense quantum states of light.
My doctoral research focused on the quantum properties of matter waves accurately described by Gaussian states. I will now explore non-Gaussian light after its interaction with matter .

news

Dec 2025	MIRO conference I had the chance to present this week our new results at the MIRO optics conference , in the University of Santiago .
Dec 2025	A new preprint on arXiv! We have just released our new work on arXiv, in which we show how to probe the quantumness of a class of non-Gaussian states, known as Generalized Coherent States, using only the intensity–field correlation function . Our findings are experimentally relevant because measuring this single, easily implementable function is sufficient to detect the nonclassicality of these states .
Nov 2025	First conference in Valparaiso! I just came back from my first conference in Chile — the Quantum Optics and Solid State Conference, QUOST IX, held in Valparaíso (Chile). It was mainly a national-level conference, which gave me a good overview of the field of quantum optics in Chile . It was also a great opportunity to meet other researchers in the field and learn about recent advances . I also had the chance to present the work I did during my PhD thesis. Many thanks to the organizers for this very nice conference!

selected publications

Phys. Rev. Lett.

Observation of Entanglement in a Cold Atom Analog of Cosmological Preheating

Victor Gondret, Clothilde Lamirault, Rui Dias, and 8 more authors

Phys. Rev. Lett., Dec 2025

Abs DOI arXiv HTML PDF

We observe entanglement between collective excitations of a Bose-Einstein condensate in a configuration analogous to particle production during the preheating phase of the early Universe. In our setup, the oscillation of the inflaton field is mimicked by the transverse breathing mode of a cigar-shaped condensate, which parametrically excites longitudinal quasiparticles with opposite momenta. After a short modulation period, we observe entanglement of these pairs that reveals the role played by vacuum fluctuations in seeding the parametric growth, confirming the quantum origin of the excitations. As the system continues to evolve, we observe a decrease in correlations and a disappearance of nonclassical features. These point toward future experimental probes of the late-time nonlinear regime where further analogies can be drawn with reheating, i.e., the thermalization of the postinflationary Universe.
Phys. Rev. Lett.

Quantifying Two-Mode Entanglement of Bosonic Gaussian States from Their Full Counting Statistics

Victor Gondret, Clothilde Lamirault, Rui Dias, and 4 more authors

Phys. Rev. Lett., Sep 2025

Abs DOI arXiv HTML PDF

We study the entanglement properties of two-mode bosonic Gaussian states based on their multi-mode counting statistics. We exploit the idea that measuring high-order correlations of particle numbers can reveal entanglement without making any assumptions about the coherence of the fields. We show that the two- and four-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 are of great importance because it becomes possible to reveal entanglement in a series of recent experiments.
Phys. Rev. A

Coherent coupling of momentum states: Selectivity and phase control

Charlie Leprince, Victor Gondret, Clothilde Lamirault, and 4 more authors

Phys. Rev. A, Jun 2025

Abs DOI arXiv HTML PDF

We demonstrate the effect of pulse shaping in momentum-selective atomic Bragg diffraction. We compare temporal square pulses, which produce sidelobes in momentum space, with other shapes that can produce more nearly square momentum distributions. We produce pulses that simultaneously address two sets of velocity classes and demonstrate that we can control the differential phase imprinted on them in a way that is insensitive to laser phase fluctuations. Our work marks a significant step forward in testing Bell inequalities using massive particles entangled in momentum.

news

MIRO conference

A new preprint on arXiv!

First conference in Valparaiso!

selected publications