Poor Man's Scaling and Green Function Analysis of the Kondo Anomaly in Single-Level Quantum Dots

Abstract

Kondo effect in a single-level quantum dot attached to magnetic leads is studied theoretically by the “poor man’s scaling” and non-equilibrium Green function methods. From the scaling equations we derive the Kondo temperature as a function of the model parameters — in particular as a function of the angle between magnetic moments. Transport characteristics, i.e. differential conductance and tunnel magnetoresistance associated with magnetization rotation, were calculated within the non-equilibrium Green function formalism based on the equation of motion method.