A quantum Monte Carlo algorithm for softcore boson systems

TL;DR

This paper introduces an efficient quantum Monte Carlo algorithm for simulating lattice bosonic systems, leveraging a spin model mapping to reduce systematic errors and improve computational performance.

Contribution

It presents a novel algorithm based on mapping bosonic models to spin models with infinite spin quantum number, explicitly eliminating systematic errors.

Findings

Algorithm effectively simulates non-interacting boson models

Performance surpasses stochastic series expansion in efficiency

Systematic error elimination enhances simulation accuracy

Abstract

An efficient Quantum Monte Carlo algorithm for the simulation of bosonic systems on a lattice in a grand canonical ensemble is proposed. It is based on the mapping of bosonic models to the spin models in the limit of the infinite total spin quantum number. It is demonstrated, how this limit may be taken explicitly in the algorithm, eliminating the systematic errors. The efficiency of the algorithm is examined for the non-interacting lattice boson model and compared with the stochastic series expansion method with the heat-bath type scattering probability of the random walker.