opendf - an implementation of the dual fermion method for strongly correlated systems

TL;DR

The paper introduces 'opendf', an open-source software implementing the dual fermion method to efficiently study strongly correlated lattice systems across multiple dimensions.

Contribution

It provides the first open-source, versatile implementation of the dual fermion approach for fermionic lattice models in various dimensions.

Findings

Successfully models strongly correlated systems in 1D to 4D.

Enables perturbative addition of spatial correlations to DMFT.

Open-source code facilitates wider adoption and testing.

Abstract

The dual fermion method is a multiscale approach for solving lattice problems of interacting strongly correlated systems. In this paper, we present the \texttt{opendf} code, an open-source implementation of the dual fermion method applicable to fermionic single-orbital lattice models in dimensions $D=1,2,3$ and $4$. The method is built on a dynamical mean field starting point, which neglects all local correlations, and perturbatively adds spatial correlations. Our code is distributed as an open-source package under the GNU public license version 2.