Kondo correlation and spin-flip scattering in spin-dependent transport through a quantum dot coupled to ferromagnetic leads

TL;DR

This paper studies how spin-flip scattering affects Kondo correlations and conductance in a quantum dot with ferromagnetic leads, revealing suppression of Kondo effects and formation of split peaks in conductance.

Contribution

It introduces a slave-boson mean field approach to analyze the impact of spin-flip scattering on Kondo physics in quantum dots with ferromagnetic contacts.

Findings

Spin-flip scattering suppresses Kondo correlations at all polarization levels.

In the Kondo regime, zero-bias conductance peaks split into two due to spin-flip.

Spin-flip processes can transform zero-bias anomalies into three-peak structures.

Abstract

We investigate the linear and nonlinear dc transport through an interacting quantum dot connected to two ferromagnetic electrodes around Kondo regime with spin-flip scattering in the dot. Using a slave-boson mean field approach for the Anderson Hamiltonian having finite on-site Coulomb repulsion, we find that a spin-flip scattering always depresses the Kondo correlation at arbitrary polarization strength in both parallel and antiparallel alignment of the lead magnetization and that it effectively reinforces the tunneling related conductance in the antiparallel configuration. For systems deep in the Kondo regime, the zero-bias single Kondo peak in the differential conductance is split into two peaks by the intradot spin-flip scattering; while for systems somewhat further from the Kondo center, the spin-flip process in the dot may turn the zero-bias anomaly into a three-peak structure.