Berry curvature of interacting bosons in a honeycomb lattice

• Main Authors: Li, Yun, Sengupta, Pinaki, Batrouni, George G., Miniatura, Christian, Grémaud, Benoît
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2015
• Subjects: Physics & Applied Physics
• Online Access: https://hdl.handle.net/10356/81126; http://hdl.handle.net/10220/39122
• Institution: Nanyang Technological University

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.