arXiv:1506.03964 · Physical Review A
Berry curvature of interacting bosons in a honeycomb lattice
Yun Li, Pinaki Sengupta, G. G. Batrouni, Christian Miniatura, Benoît Grémaud
Abstract
We consider soft-core bosons with on-site interaction loaded in the honeycomb lattice with different site energies for the two sublattices. Using both a mean-field approach and quantum Monte Carlo simulations, we show that the topology of the honeycomb lattice results in a nonvanishing Berry curvature for the band structure of the single-particle excitations of the system. This Berry curvature induces an anomalous Hall effect when driving the system out of equilibrium. It is seen by studying the time evolution of a wave packet, namely, a superfluid ground state in a harmonic trap, subjected either to a constant force (Bloch oscillations) or to a sudden shift of the trap center.