Quantum Transport and Integrability of the Anderson Model for a Quantum Dot with Multiple Leads

TL;DR

This paper demonstrates the integrability of an Anderson model for a quantum dot with multiple leads and derives a non-linear conductance formula, revealing complex Kondo resonance splitting phenomena.

Contribution

It provides the first exact solution for the conductance of a multi-lead quantum dot Anderson model using Bethe ansatz and Landauer-Büttiker theory.

Findings

Exact expression for non-linear conductance in multi-lead quantum dots.

Identification of bias-induced Kondo resonance splitting for three or more leads.

Multiple Kondo peaks can occur at different chemical potentials.

Abstract

We show that an Anderson Hamiltonian describing a quantum dot connected to multiple leads is integrable. A general expression for the non-linear conductance is obtained by combining the Bethe ansatz exact solution with Landauer-B\"uttiker theory. In the Kondo regime, a closed form expression is given for the matrix conductance at zero temperature and when all the leads are close to the symmetric point. A bias-induced splitting of the Kondo resonance is possible for three or more leads. Specifically, for $N$ leads, with each at a different chemical potential, there can be $N-1$ Kondo peaks in the conductance.