$i$QIST: An open source continuous-time quantum Monte Carlo impurity solver toolkit

TL;DR

The paper introduces $i$QIST, an open-source toolkit of optimized continuous-time quantum Monte Carlo impurity solvers designed for studying strongly correlated electron systems, with detailed implementation and usage tutorials.

Contribution

It provides a comprehensive, optimized, open-source toolkit of quantum impurity solvers based on the hybridization expansion continuous-time quantum Monte Carlo algorithm, including implementation details and tutorials.

Findings

Efficient implementation of quantum impurity solvers

Versatile toolkit for strongly correlated systems

User-friendly with tutorials and optimization strategies

Abstract

Quantum impurity solvers have a broad range of applications in theoretical studies of strongly correlated electron systems. Especially, they play a key role in dynamical mean-field theory calculations of correlated lattice models and realistic materials. Therefore, the development and implementation of efficient quantum impurity solvers is an important task. In this paper, we present an open source interacting quantum impurity solver toolkit (dubbed $i$QIST). This package contains several highly optimized quantum impurity solvers which are based on the hybridization expansion continuous-time quantum Monte Carlo algorithm, as well as some essential pre- and post-processing tools. We first introduce the basic principle of continuous-time quantum Monte Carlo algorithm and then discuss the implementation details and optimization strategies. The software framework, major features, and installation procedure for $i$QIST are also explained. Finally, several simple tutorials are presented in order to demonstrate the usage and power of $i$QIST.