Widely existing mixed phase structure of quantum dimer model on square lattice

TL;DR

This paper uses a new computational method to clarify the phase diagram of the quantum dimer model on a square lattice, providing strong evidence for the widespread existence of a mixed phase state.

Contribution

It introduces a sweeping cluster algorithm and new correlation measures to accurately identify the mixed phase in the quantum dimer model.

Findings

The mixed phase exists over a large parameter region.

The ground state is predominantly in the mixed phase.

The method improves phase identification accuracy.

Abstract

Since constraints hinder the application of numerical algorithms, phase diagrams of quantum dimer models are still controversial, even on the square lattice. The core controversy is whether the mixed state exists. In this article, we give strong evidences to solve this dispute. With our newly developed sweeping cluster method, we studied the phase diagram of large parameter space by introducing the definition of pair correlation function and other supporting evidence to distinguish the mixed phase from the columnar phase with high precision. In particular, we find that the ground state corresponds to the mixed phase for a vast parameter region.