Simon Böhly — University of Padova #
Probing universal relaxation speed in a Bose-Einstein condensate far from equilibrium #
The dynamics of a Bose-Einstein condensate initialized in a far-from-equilibrium state can exhibit behavior that is reminiscent of fixed points in phase transitions—namely, self-similar scaling and universality. This phenomenon is referred to as a “non-thermal fixed point”. The properties of non-thermal fixed points enable predictions about the system’s relaxation dynamics, particularly the speed at which relaxation occurs. Dimensional analysis suggests that the relaxation speed exhibits universality—that is, counterintuitively, it does not depend on microscopic details such as the condensate’s density or interaction strength or on the exact initial state. Recent experimental results support this prediction (arXiv:2410.08204 [cond-mat.quant-gas]). In this poster, I will first introduce the concept of non-thermal fixed points and their connection to relaxation dynamics. I will discuss results based on numerical simulations and analytical approaches, addressing the question: “To what extent is the relaxation speed in a far-from-equilibrium Bose-Einstein condensate universal?”