Title: 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 point at which the
system begins to forget its initial symmetry state. We further identify a
symmetry gap in the low lying excited states which trends with the symmetry
memory.