Nonequilibrium Anderson model made simple with density functional theory

TL;DR

This paper develops a simplified density functional theory approach within the i-DFT framework to accurately model electron transport in the Anderson model across various conditions, enabling efficient calculations of differential conductance.

Contribution

The authors construct an approximation for the exchange-correlation bias and on-site potential that works across a wide range of parameters, simplifying the analysis of the Anderson model.

Findings

Accurate approximation for xc bias and on-site potential across temperatures, gates, and biases.

Provides a simple, unifying framework for differential conductance calculations.

Advances DFT methods for correlated electron systems.

Abstract

The single-impurity Anderson model is studied within the i-DFT framework, a recently proposed extension of density functional theory (DFT) for the description of electron transport in the steady state. i-DFT is designed to give both the steady current and density at the impurity, and it requires the knowledge of the exchange-correlation (xc) bias and on-site potential (gate). In this work we construct an approximation for both quantities which is accurate in a wide range of temperatures, gates and biases, thus providing a simple and unifying framework to calculate the differential conductance at negligible computational cost in different regimes. Our results mark a substantial advance for DFT and may inform the construction of functionals applicable to other correlated systems.