Reservoir Interactions during Bose-Einstein Condensation: Modified Critical Scaling in the Kibble-Zurek Mechanism of Defect Formation

Abstract

As a test of the Kibble–Zurek mechanism (KZM) of defect formation, we simulate the Bose–Einstein condensation transition in a toroidally confined Bose gas by using the stochastic projected Gross–Pitaevskii equation, with and without the energy-damping reservoir interaction. Energy-damping alters the scaling of the winding-number distribution with the quench time—a departure from the universal KZM theory that relies on equilibrium critical exponents. Numerical values are obtained for the correlation-length critical exponent ν and the dynamical critical exponent z for each variant of reservoir interaction theory. The energy-damping reservoir interactions cause significant modification of the dynamical critical exponent of the phase transition, while preserving the essential KZM critical scaling behavior. Comparison of numerical and analytical two-point correlation functions further illustrates the effect of energy damping on the correlation length during freeze-out.

Publication
Physical Review A