DSQSS: Discrete Space Quantum Systems Solver

TL;DR

DSQSS is a versatile software package that employs quantum Monte Carlo methods to solve complex quantum many-body problems on lattices, supporting various models, dimensions, and finite temperature calculations.

Contribution

The paper introduces DSQSS, a flexible and comprehensive solver for lattice quantum many-body problems using quantum Monte Carlo techniques, with detailed usage and applications.

Findings

Successfully performs finite temperature calculations for quantum spin models.

Supports arbitrary lattice structures and interaction parameters.

Demonstrates applicability to various quantum many-body systems.

Abstract

The Discrete Space Quantum Systems Solver (DSQSS) is a program package for solving quantum many-body problems defined on lattices. The DSQSS is based on the quantum Monte Carlo method in Feynman's path integral representation and covers a broad range of problems using flexible input files that define arbitrary unit cells in arbitrary dimensions and arbitrary matrix elements representing the interactions among an arbitrary number of degrees of freedom. Finite temperature calculations of quantum spin and the Bose- Hubbard models can be performed by specifying parameters such as the number of dimensions, the lattice size, coupling constants, and temperature. The present paper details the use of DSQSS and presents a number of applications thereof.