The effect of disorder on the phase diagrams of hard-core lattice bosons with cavity-mediated long-range and nearest-neighbor interactions

TL;DR

This study uses quantum Monte Carlo simulations to explore how disorder affects the phase diagrams of a two-dimensional Bose-Hubbard model with long-range and nearest-neighbor interactions, revealing suppression of metastable states and superfluidity, and identifying glassy phases.

Contribution

It provides a detailed analysis of the impact of disorder on phase stability and introduces the existence of glassy phases in the extended Bose-Hubbard model with long-range interactions.

Findings

Disorder suppresses metastable states and superfluidity.

A supersolid phase exists at weak disorder in the long-range interaction model.

Two glassy phases, Bose glass and disordered solid, are identified.

Abstract

We use quantum Monte Carlo simulations with the worm algorithm to study the phase diagram of a two-dimensional Bose-Hubbard model with cavity-mediated long-range interactions and uncorrelated disorder in the hard-core limit. Our study shows the system is in a supersolid phase at weak disorder and a disordered solid phase at stronger disorder. Due to long-range interactions, a large region of metastable states exists in both clean and disordered systems. By comparing the phase diagrams for both clean and disordered systems, we find that disorder suppresses metastable states and superfluidity. We compare these results with the phase diagram of the extended Bose-Hubbard model with nearest-neighbor interactions. Here, the supersolid phase does not exist even at weak disorder. We identify two kinds of glassy phases: a Bose glass phase and a disordered solid phase. The glassy phases intervene between the density-wave and superfluid phases as the Griffiths phase of the Bose-Hubbard model. The disordered solid phase intervenes between the density-wave and Bose glass phases since both have a finite structure factor.