Quantum Optics Seminar by Benjamin Pasquiou

Cold and ultracold strontium for quantum simulation and sensing

In this seminar, I will talk about two of the experiments of our group “Magnetic Quantum Gases” in the Laboratoire de Physique des Lasers (LPL) in Villetaneuse, that rely cold and ultracold strontium.

In the first apparatus, we are using a Fermi sea with a high spin degree of freedom, namely between 1 and 10 spin states, as a quantum simulator for studying quantum magnetism phenomena. We are interested in observing the dynamics of formation of quantum correlations when atoms interact with each other inside optical lattices. I will describe our solutions to prepare low entropy samples, to produce micro-structured spin textures, and to detect the independent spin components [1,2].

In our second apparatus, we are developing a CW superradiant laser on the not-so-narrow (7 kHz) intercombination line of strontium, by guiding a 10-100 m/s fast continuous atomic beam through the mode of a “bad” optical cavity. One of our goals is to study the correlations that, according to our recent findings [3], should arise between atoms, especially near the superradiant lasing threshold. 

[1] P. Bataille, A. Litvinov, I. Manai, J. Huckans, F. Wiotte, A. Kaladjian, O. Gorceix, E. Maréchal, B. Laburthe-Tolra, and M. Robert-de-Saint-Vincent, Adiabatic Spin-Dependent Momentum Transfer in an SU( N ) Degenerate Fermi Gas, Phys. Rev. A 102, 013317 (2020).

[2] A. Litvinov, P. Bataille, E. Maréchal, P. Pedri, O. Gorceix, M. R.-d. Saint-Vincent, and B. Laburthe-Tolra, Measuring Densities of Cold Atomic Clouds Smaller Than the Resolution Limit, Phys. Rev. A 104, 033309 (2021). 

[3] Bruno Laburthe-Tolra, Ziyad Amodjee, Benjamin Pasquiou, Martin Robert-de-Saint-Vincent, Correlations and linewidth of the atomic beam continuous superradiant laser, arXiv: 2210.05464 (2022, accepted SciPost Physics Core).