AMO Seminar - Professor Kazuya Fujimoto

Abstract

Ultracold atomic gases have been one of the most suitable systems to study universal non-equilibrium dynamics such as the Kibble-Zurek mechanism and phase ordering kinetics. Recently, non-thermal fixed points (NTFPs) have attracted great interest in the field. This is a scenario for universal thermalization originally proposed in quark-gluon plasmas, and two experimental groups, recently, have observed universal dynamics related to NTPFs in one-dimensional (1D) scalar and spinor Bose gases [1,2]. However, fundamental mechanisms behind 1D NTFPs has been elusive. In this seminar, we show our theoretical results for universal relaxation dynamics in a 1D antiferromagnetic spinor Bose gas [3]. Employing the truncated Wigner approximation, we find the scale-invariant universal relaxation phenomenon consistent with the NTFP scenario, and uncover that magnetic solitons play an important role in emergence of the universal behavior.