Current and Noise in a FM/quantum dot/FM System

TL;DR

This paper investigates how spin-flip scattering influences current, noise, and tunneling magnetoresistance in a ferromagnetic-quantum dot-ferromagnetic system using nonequilibrium quantum techniques.

Contribution

It provides a detailed analysis of the effects of spin-flip scattering on transport properties in FM-QD-FM systems, highlighting the suppression of tunneling magnetoresistance.

Findings

Spin-flip increases AP-current and AP-noise.

P-current and P-noise are insensitive to spin-flip.

Tunneling magnetoresistance decreases with higher spin-flip rate.

Abstract

Using the Keldysh nonequilibrium technique we calculate current, noise and Fano factor in a ferromagnetic(FM)-quantum dot-ferromagnetic(FM) system with Coulomb interaction and spin-flip scattering in the dot. The lead polarizations are considered in both parallel P and antiparallel AP alignments. We show that spin-flip can increase both AP-current and AP-noise, while the P-current and P-noise are almost insensible to it. This fact leads to a suppression of the tunnelling magnetoresistance with increasing spin-flip rate.