Kondo effect given exactly by density functional theory

TL;DR

This paper demonstrates that the exact Kohn-Sham potential from density functional theory can precisely reproduce the linear transport properties of an Anderson junction, capturing the Kondo effect without explicitly modeling the Kondo peak.

Contribution

It provides an exact calculation of the Kohn-Sham potential across all coupling strengths using Bethe ansatz, revealing how DFT captures Kondo physics.

Findings

Exact Kohn-Sham potential reproduces transport properties

Interpolation formula accurately models potential across couplings

Kondo physics captured without explicit Kondo peak in spectral function

Abstract

Transport through an Anderson junction (two macroscopic electrodes coupled to an Anderson impurity) is dominated by a Kondo peak in the spectral function at zero temperature. The exact single-particle Kohn-Sham potential of density functional theory reproduces the linear transport exactly, despite the lack of a Kondo peak in its spectral function. Using Bethe ansatz techniques, we calculate this potential exactly for all coupling strengths, including the cross-over from mean-field behavior to charge quantization caused by the derivative discontinuity. A simple and accurate interpolation formula is also given.