A striped supersolid phase and the search for deconfined quantum criticality in hard-core bosons on the triangular lattice

TL;DR

This paper uses quantum Monte Carlo simulations to explore complex phases of hard-core bosons on a triangular lattice, discovering a unique striped supersolid state and examining phase transitions, including the search for deconfined quantum criticality.

Contribution

It identifies a novel striped supersolid phase at 1/2-filling and investigates various phase transitions, including the absence of deconfined quantum critical points.

Findings

Discovery of a stable striped supersolid at 1/2-filling

Analysis of superfluid and Mott insulator phase transitions

No evidence of deconfined quantum criticality found

Abstract

Using large-scale quantum Monte Carlo simulations we study bosons hopping on a triangular lattice with nearest (V) and next-nearest (V') neighbor repulsive interactions. In the limit where V=0 but V' is large, we find an example of an unusual period-three striped supersolid state that is stable at 1/2-filling. We discuss the relationship of this state to others on the rich ground-state phase diagram, which include a previously-discovered nearest-neighbor supersolid, a uniform superfluid, as well as several Mott insulating phases. We study several superfluid- and supersolid-to-Mott phase transitions, including one proposed by a recent phenomenological dual vortex field theory as a candidate for an exotic deconfined quantum critical point. We find no examples of unconventional quantum criticality among any of the interesting phase transitions in the model.