Equilibrium angular momentum and edge current in Bose-condensed cold atom systems with k-space Berry curvature

In this paper we study the properties of cold bosons in a two-dimensional optical lattice system where Bose-condensation occurs at a momentum point k with non-zero k-space Berry curvature. By combining results from both analytic and numerical approaches, we show that the boson system carries non-universal, temperature dependent equilibrium angular momentum and edge current at low temperatures.