Nonequilibrium quantum dynamics of partial symmetry breaking for ultracold bosons in an optical lattice ring trap

Abstract

A vortex in a Bose-Einstein condensate on a ring undergoes quantum dynamics in response to a quantum quench in terms of partial symmetry breaking from a uniform lattice to a biperiodic one. Neither the current, a macroscopic measure, nor fidelity, a microscopic measure, exhibit critical behavior. Instead, the symmetry memory succeeds in identifying the critical symmetry breaking at which the system begins to forget its initial symmetry state. We further identify a symmetry energy difference in the low lying excited states which trends with the symmetry memory.

Quench dynamics and atom number parity effect of bosonic condensates in a double-well potential

“…The exchange invariance means that the spectra can also be understood in the view of symmetry. For example, Zhao et al [50] investigates the eigenspectra and the quench dynamics in an optical lattice ring trap with an initial vortex state, and shows that the nonequilibrium dynamics of the system manifests critical behavior, depending on the value of symmetry breaking.…”