Finite-temperature phase structures of hard-core bosons in an optical lattice with an effective magnetic field

TL;DR

This paper investigates the finite-temperature phase behavior of hard-core bosons in a 2D optical lattice under an effective magnetic field using Monte Carlo simulations, revealing similarities to the frustrated XY model.

Contribution

It introduces a gauged CP^1 model approach to analyze phase structures of hard-core bosons at finite temperatures with various magnetic fluxes and densities.

Findings

Thermodynamic properties resemble those of the frustrated XY model.

Cold atom simulators can effectively emulate the frustrated XY model regardless of particle filling.

Particle number fluctuations do not significantly alter the phase structure.

Abstract

We study finite-temperature phase structures of hard-core bosons in a two-dimensional optical lattice subject to an effective magnetic field by employing the gauged CP$^1$ model. Based on the extensive Monte Carlo simulations, we study their phase structures at finite temperatures for several values of the magnetic flux per plaquette of the lattice and mean particle density. Despite the presence of the particle number fluctuation, the thermodynamic properties are qualitatively similar to those of the frustrated XY model with only the phase as a dynamical variable. This suggests that cold atom simulators of the frustrated XY model are available irrespective of the particle filling at each site.