Supersolid phase of hardcore bosons on triangular lattice

TL;DR

This paper investigates the supersolid phase of hardcore bosons on a triangular lattice, characterizing its order, phase diagram, and finite-temperature transitions, revealing unique phase behaviors and critical phenomena.

Contribution

It provides a detailed analysis of the supersolid phase and phase transitions in hardcore bosons on a triangular lattice, highlighting novel phase order and critical transition types.

Findings

Solid order is of the (2m,-m',-m') type with discontinuous change at half-filling

Finite temperature phase diagram includes intersecting second-order transition lines

Transitions include 3-state Potts and Kosterlitz-Thouless universality classes

Abstract

We establish the nature of the supersolid phase observed for hardcore bosons on the triangular lattice near half-integer filling factor, and study the phase diagram of the system at finite temperature. We find that the solid order is always of the (2m,-m',-m') with m changing discontinuously from positive to negative values at half-filling, contrary to predictions of other phases, based on an analogy with the properties of Ising spins in transverse magnetic field. At finite temperature we find two intersecting second-order transition lines, one in the 3-state Potts universality class and the other of the Kosterlitz-Thouless type.