Mean-field embedding of the dual fermion approach for correlated electron systems

TL;DR

This paper introduces two embedding schemes for the dual fermion approach to efficiently study correlated electron systems, significantly reducing computational costs while maintaining accuracy.

Contribution

The authors propose real fermion and dual fermion embedding methods that accelerate convergence in dual fermion calculations for large systems.

Findings

Embedding schemes converge to similar results.

Embedding approaches outperform conventional dual fermion method in convergence speed.

Methods are effective for Anderson disorder and Hubbard models.

Abstract

To reduce the rapidly growing computational cost of the dual fermion lattice calculation with increasing system size, we introduce two embedding schemes. One is the real fermion embedding, and the other is the dual fermion embedding. Our numerical tests show that the real fermion and dual fermion embedding approaches converge to essentially the same result. The application on the Anderson disorder and Hubbard models shows that these embedding algorithms converge more quickly with system size as compared to the conventional dual fermion method, for the calculation of both single-particle and two-particle quantities.