Alternative equation of motion approach applied to transport through a Quantum Dot

TL;DR

This paper introduces an alternative equation of motion method to analyze non-equilibrium electron transport in quantum dots, successfully capturing the Kondo resonance and calculating conductance properties under various conditions.

Contribution

The authors develop a novel equation of motion approach that differentiates Green functions over both time variables, enabling accurate modeling of Kondo states and transport properties in quantum dots.

Findings

Successfully reproduces the Kondo resonance in symmetric and asymmetric cases.

Calculates density of states and differential conductance as functions of bias voltage.

Analyzes the effects of temperature and Coulomb interaction on conductance.

Abstract

We study non-equilibrium electron transport through a quantum dot coupled to metallic leads. We use an alternative equation of motion approach in which we calculate the retarded Green function of the impurity by differentiating Green functions over both time variables. Such an approach allows us to obtain the resonance Kondo state in the particle-hole symmetric case and in the asymmetric cases. We apply this technique for calculating the density of the states of quantum dot and the differential conductance as a function of bias voltage. The differential conductance dependence on temperature and on Coulomb interaction is also calculated.