Local Spin-Gauge Symmetry of the Bose-Einstein Condensates in Atomic Gases.

Abstract

The Bose-Einstein condensates of alkali atomic gases are spinor fields with local ``spin-gauge'' symmetry. This symmetry is manifested by a superfluid velocity ${\mathbf{u}}_{s}$ (or gauge field) generated by the Berry phase of the spin field. In ``static'' traps, ${\mathbf{u}}_{s}$ splits the degeneracy of the harmonic energy levels, breaks the inversion symmetry of the vortex nucleation frequency ${\mathbf{\ensuremath{\Omega}}}_{c1}$, and can lead to vortex ground states.