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Max Schemmer, PhD. Laboratoire Charles Fabry, Institut d’Optique, CNRS, Université Paris-Saclay

Event Date: 
Monday, March 11, 2019 - 3:30pm to 4:30pm

Generalized Hydrodynamics on an Atom Chip

I will present an experimental test [1] of the new theory of Generalized HydroDynamics (GHD), introduced in 2016 to describe long wave-length dynamics of one-dimensional (1D) quantum integrable systems. Integrable systems posses an infinite number of conserved quantities and GHD takes into account the conservation of all of them. We monitor a single 1D cloud of bosonic atoms which are trapped on an atom chip. We suddenly modify the longitudinal trapping potential and observe the time evolution of the in situ atomic density profiles. The weakly interacting atomic clouds lie at the crossover between the quasi-condensate regime and the ideal Bose gas regime. Predictions of GHD are in very good agreement with the experiment. Previously existing theories such as the “conventional” hydrodynamic approach which relies on the assumption of a local thermal equilibrium, described by a Gibbs ensemble, are unable to reproduce the experimental data.

If time is left I will present the cooling of a Bose gas by three-body losses [2]. Three-body losses are typically associated with heating in cold atom experiments. We use a 1D Bose gas in the quasi-condensate regime on an atom chip experiment. While three-body losses continuously reduce the density of the system the temperature T drops up to a factor of four. The results are in good agreement with theoretical predictions.

[1] Schemmer, Max, et al. "Generalized hydrodynamics on an atom chip." arXiv preprint arXiv:1810.07170 (2018).

[2] Schemmer, Max, and Isabelle Bouchoule. "Cooling a Bose gas by three-body losses." Physical review letters 121.20 (2018): 200401.

I obtained my bachelor degree at the University of Freiburg, Germany and my master degree from the École Normale Supérieure de Lyon, France. I specialized in cold atom physics and finished my master with an internship in the group of Ian Spielman at NIST Gaithersburg, USA. Currently, I am finishing my PhD at the Laboratoire Charles Fabry in Palaiseau, France. In my PhD I work with an atom chip experiment on the out-of-equilibrium dynamics of 1D Bose gases.

 

Event Location: 
McMaster
Location Details: 
ABB-162