Disorder and interactions in systems out of equilibrium: The exact independent-particle picture from density functional theory

TL;DR

This paper demonstrates how density functional theory can be used to exactly analyze non-equilibrium disordered systems with interactions, revealing how interactions influence disorder and current.

Contribution

It introduces a method to obtain the exact effective potential and bias in non-equilibrium disordered systems using DFT, highlighting its diagnostic potential.

Findings

Interactions smoothen the effective disorder landscape

Interactions do not necessarily increase current due to competing effects

DFT can diagnose disorder screening in complex systems

Abstract

Density functional theory (DFT) exploits an independent-particle-system construction to replicate the densities and current of an interacting system. This construction is used here to access the exact effective potential and bias of non-equilibrium systems with disorder and interactions. Our results show that interactions smoothen the effective disorder landscape, but do not necessarily increase the current, due to the competition of disorder screening and effective bias. This puts forward DFT as a diagnostic tool to understand disorder screening in a wide class of interacting disordered systems.