Green's function formulation of quantum defect embedding theory

TL;DR

This paper introduces a Green's function approach to quantum defect embedding theory (QDET), rigorously deriving a double counting scheme within the $G_0 W_0$ approximation and demonstrating its effectiveness on defects in diamond.

Contribution

The paper develops a Green's function formulation of QDET with a new double counting correction scheme and explores strategies for convergence with respect to active space size and composition.

Findings

QDET with the new scheme effectively describes defect states in diamond

The methodology shows robustness across different defect types

Convergence strategies improve the reliability of results

Abstract

We present a Green's function formulation of the quantum defect embedding theory (QDET) where a double counting scheme is rigorously derived within the $G_0 W_0$ approximation. We then show the robustness of our methodology by applying the theory with the newly derived scheme to several defects in diamond. Additionally, we discuss a strategy to obtain converged results as a function of the size and composition of the active space. Our results show that QDET is a promising approach to investigate strongly correlated states of defects in solids.