Bosons in optical lattice

Ultracold atoms is a system that particles (fermions or/and bosons) are cooled down to a very low temperature using lasers and magnetic fields. The temperature is low enough that the particles exhibit quantum phenomena, for example, Bose-Einsten condensation. The essential parameters of the system, including the interaction, the shape, and the lattice geometry, can be greatly controlled in the experiments.

In our works, we determine the quantum critical region close to the phase transitions. In another work, we study the two-component bosons in optical lattice where a pair-supersolid state can be stabilized. We explore the phase diagram including Mott insulator, pair-superfluid and pair-supersolid.

The simulations are performed using quantum Monte Carlo.