Sommaire:

The study of out-of-equilibrium thermodynamics has received a significant thrust thanks to the experimental advances in the control and manipulation of microscopic systems. Work, an ubiquitous concept in traditional thermodynamics, assumes in this context the role of a stochastic variable whose fluctuations can be ingeniously related to equilibrium properties, as is the case of the celebrated Jarzynski equality. In this talk, I will revise these concepts and discuss a feasible experimental scheme to directly measure work in cold atomic setups. I will show that the interaction between atoms and the light polarisation of a probe laser, as in atomic ensembles experiments, allows us to implement such POVM. In this way the work done on or extracted from the atoms after a given process is encoded in the light quadrature that can be measured with a standard homodyne detection. The protocol allows one to verify fluctuation theorems and study properties of the non-unitary dynamics of a given thermodynamic process [1]. A second scheme allows one to measure the work done on an atomic BEC in a double well potential when the atomic self-interaction is varied. I will discuss strategies based on optimal control techniques to reduce the irreversible work production.

References
G. De Chiara, A. J. Roncaglia, J. P. Paz, New J. Phys. 17, 035004 (2015)

Pour plus d'informations, merci de contacter Antezza M.