Non-equilibrium theory for strongly coupled quantum dot with arbitrary on-site correlation strength

TL;DR

This paper develops an analytical method to accurately calculate current through a quantum dot with arbitrary electron-electron interaction strength, incorporating strong correlation effects beyond mean-field approximations.

Contribution

It introduces a diagrammatic technique for strong coupling that includes electron correlations in quantum dot transport calculations, extending beyond standard mean-field theory.

Findings

Transport properties match recent experimental data

Method works for arbitrary on-site interaction strength

Provides a new analytical expression for quantum dot current

Abstract

An analytical expression for the current through a single level quantum dot for arbitrary strength of the on-site electron-electron interaction is derived beyond standard mean-field theory. By describing the localised states in terms of many-body operators, the employed diagrammatic technique for strong coupling enables inclusion of electron correlation effects into the description of the local dynamics, which provides transport properties that are consistent with recent experimental data.