Phase Structure of Repulsive Hard-Core Bosons in a Stacked Triangular Lattice

TL;DR

This study explores the phase diagram of hard-core bosons with repulsive interactions in a stacked triangular lattice, revealing various phases including solid, superfluid, and supersolid states through Monte Carlo simulations.

Contribution

It provides the first detailed phase diagram of this three-dimensional system, highlighting the effects of stacking and temperature on phase stability.

Findings

Existence of solid states at densities 1/3 and 2/3

Identification of superfluid and supersolid phases

Comparison with 2D triangular lattice phase diagram

Abstract

In this paper, we study phase structure of a system of hard-core bosons with a nearest-neighbor (NN) repulsive interaction in a stacked triangular lattice. Hamiltonian of the system contains two parameters one of which is the hopping amplitude $t$ between NN sites and the other is the NN repulsion $V$. We investigate the system by means of the Monte-Carlo simulations and clarify the low and high-temperature phase diagrams. There exist solid states with density of boson $\rho={1 \over 3}$ and ${2\over 3}$, superfluid, supersolid and phase-separated state. The result is compared with the phase diagram of the two-dimensional system in a triangular lattice at vanishing temperature.