Commensurate lock-in and incommensurate supersolid phases of hardcore bosons on anisotropic triangular lattices

TL;DR

This paper explores the complex phase diagram of hardcore bosons on anisotropic triangular lattices, revealing a transition from discrete jumps to continuous incommensurate supersolid phases as system size increases.

Contribution

It combines numerical and analytical methods to uncover the emergence of incommensurate supersolid phases in the thermodynamic limit, advancing understanding of quantum phase transitions.

Findings

Existence of multiple supersolid phases with density wavevector jumps in finite systems

Vanishing of density wavevector jumps in the thermodynamic limit leading to incommensurate phases

Identification of continuous incommensurate supersolid phases in large systems

Abstract

We investigate the interplay between commensurate lock-in and incommensurate supersolid phases of the hardcore bosons at half-filling with anisotropic nearest-neighbor hopping and repulsive interactions on triangular lattice. We use numerical quantum and variational Monte Carlo as well as analytical Schwinger boson mean-field analysis to establish the ground states and phase diagram. It is shown that, for finite size systems, there exist a series of jumps between different supersolid phases as the anisotropy parameter is changed. The density ordering wavevectors are locked to commensurate values and jump between adjacent supersolids. In the thermodynamic limit, however, the magnitude of these jumps vanishes leading to a continuous set of novel incommensurate supersoild phases.