Spontaneously broken gauge symmetry in a Bose gas with constant particle number

Abstract

The interplay between spontaneously broken gauge symmetries and Bose-Einstein condensation has long been controversially discussed in science, since the equation of motions are invariant under phase transformations. Within the present model it is illustrated that spontaneous symmetry breaking appears as a non-local process in position space, but within disjoint subspaces of the underlying Hilbert space. Numerical simulations show that it is the symmetry of the relative phase distribution between condensate and non-condensate quantum fields which is spontaneously broken when passing the critical temperature for Bose-Einstein condensation. Since the total number of gas particles remains constant over time, the global U(1)-gauge symmetry of the system is preserved.

4 pages, 2 figures, final version

References in corpus (4)

• Noise Thermometry with Two Weakly Coupled Bose-Einstein Condensates
• A number-conserving approach to a minimal self-consistent treatment of condensate and non-condensate dynamics in a degenerate Bose gas
• The origin of phase in the interference of Bose-Einstein condensates
• Number-conserving master equation theory for a dilute Bose-Einstein condensate