Domaines
Condensed matter
Low dimension physics
Non-equilibrium Statistical Physics
Quantum gases
Type of internship
Expérimental Description
In cold atom experiments, it is possible to realize one-dimensional (1D) gases by freezing out the transverse degrees of freedom. The effective 1D interactions between atoms are well modeled by contact interactions. We thus realize the Lieb-Liniger model which describes 1D Bosons with contact interactions. This paradigmatic model of N-body physics belongs to the class of integrable models. As a consequence the system supports quasi-particles of infinite lifetime, labeled by their velocity called rapidity. Owing to their infinite lifetime, the distribution of rapidities is constant over time. Thus the system, if prepared with a non-thermal rapidity distribution, will never relax to a thermal state. This is in contrast to ergodic systems which relaxe, with respect to local observables, towards a thermal state. Preparing an integrable system in a non-thermal state and characterizing the latter will be a major advance.
We aim to achieve non-thermal states of 1D Bose gas in the LCF atom chip experiment by implementing losses, since, accroding to theoretical studies, losses should produce non-thermal states.
The characterization of the system will be done using the measurement protocol of the rapidity distribution recently implemented on our experiment. During this internship, the student will will install the device which allows losses to be achieved by microwave coupling to a non-trapped state and he/she will participate to the implementation on the atoms.
Contact
Isabelle Bouchoule