Rejection-free cluster Wang-Landau algorithm for hard-core lattice gases

TL;DR

This paper presents a rejection-free, flat histogram cluster algorithm for efficiently sampling low entropy states in hard-core lattice gases, outperforming traditional methods especially for large excluded volume cases.

Contribution

The authors introduce a novel rejection-free cluster algorithm that accurately samples the density of states in hard-core lattice gases, including cases with large excluded volume.

Findings

Successfully reproduces known results for k=1,2,3 on square and cubic lattices.

Outperforms local move and unbiased cluster algorithms in accuracy and convergence.

Efficiently samples low entropy states difficult for traditional methods.

Abstract

We introduce a rejection-free, flat histogram, cluster algorithm to determine the density of states of hard-core lattice gases. We show that the algorithm is able to efficiently sample low entropy states that are usually difficult to access, even when the excluded volume per particle is large. The algorithm is based on simultaneously evaporating all the particles in a strip and reoccupying these sites with a new appropriately chosen configuration. We implement the algorithm for the particular case of the hard-core lattice gas in which the first k next-nearest neighbors of a particle are excluded from being occupied. It is shown that the algorithm is able to reproduce the known results for k = 1,2,3 both on the square and cubic lattices. We also show that, in comparison, the corresponding flat histogram algorithms with either local moves or unbiased cluster moves are less accurate and do not converge as the system size increases.