One-dimensional Bose gas dynamics: Breather relaxation

One-dimensional Bose gases are a useful testing ground for quantum dynamics in many-body theory. They allow experimental tests of many-body theory predictions in an exponentially complex quantum system. Here we calculate the dynamics of a higher-order soliton in the mesoscopic case of N = 10(3)-10(4) particles, giving predictions for quantum soliton breather relaxation. These quantum predictions use a truncated Wigner approximation, which is a 1/N expansion, in a regime where other exactly known predictions are recovered to high accuracy. Such dynamical calculations are testable in forthcoming Bose-Einstein-condensate experiments.