Sign-problem-free Monte Carlo simulation of certain frustrated quantum magnets

TL;DR

This paper presents a new Quantum Monte Carlo method that efficiently simulates certain frustrated quantum magnets without the sign problem, using a basis of total spin eigenstates to overcome previous limitations.

Contribution

The authors develop a sign-problem-free QMC approach for frustrated $S=1/2$ models, advancing simulation capabilities for complex quantum magnetic systems.

Findings

Efficient simulation of a broad class of frustrated quantum magnets.

Identification of limitations and potential improvements of the new method.

Demonstration of the method's effectiveness in avoiding the sign problem.

Abstract

We introduce a Quantum Monte Carlo (QMC) method which efficiently simulates in a sign-problem-free way a broad class of frustrated $S=1/2$ models with competing antiferromagnetic interactions. Our scheme uses the basis of total spin eigenstates of clusters of spins to avoid the severe sign problem faced by other QMC methods. We also flag important limitations of the new method, and comment on possibilities for further progress.