Spin-Dependent Transport Through An Interacting Quantum Dot

TL;DR

This paper investigates how spin-dependent electron transport occurs through an interacting quantum dot connected to magnetic electrodes, focusing on the Kondo effect and how internal magnetization influences conductance and resonance splitting.

Contribution

It introduces a formula for spin-dependent current in a quantum dot system and explores the control of Kondo resonance and spin splitting via electrode magnetization.

Findings

Kondo resonance can be tuned by electrode magnetization.

Parallel magnetic electrodes produce two spin-resolved conductance peaks.

Spin-flip processes split the Kondo resonance into three peaks.

Abstract

We study the nonequilibrium spin transport through a quantum dot containing two spin levels coupled to the magnetic electrodes. A formula for the spin-dependent current is obtained and is applied to discuss the linear conductance and magnetoresistance in the interacting regime, where the so-called Kondo effect arises. We show that the Kondo resonance and the correlation-induced spin splitting of the dot levels may be systematically controlled by internal magnetization in the electrodes. As a result, when the electrodes are in parallel magnetic configuration, the linear conductance is characterized by two spin-resolved peaks. Furthermore, the presence of the spin-flip process in the dot splits the Kondo resonance into three peaks.