Theory of Transport through Quantum-Dot Spin Valves in the Weak-Coupling Regime

TL;DR

This paper develops a comprehensive theoretical framework for electron transport in quantum-dot spin valves, accounting for non-collinear magnetizations, external magnetic fields, and both linear and nonlinear regimes, predicting novel conductance phenomena.

Contribution

It introduces a generalized rate equation approach for weakly coupled quantum dots with ferromagnetic leads, including spin effects and non-collinear configurations.

Findings

Prediction of negative differential conductance

Dependence of conductance on lead magnetization angle

Influence of external magnetic field on transport

Abstract

We develop a theory of electron transport through quantum dots that are weakly coupled to ferromagnetic leads. The theory covers both the linear and nonlinear transport regime, takes non-collinear magnetization of the leads into account, and allows for an externally-applied magnetic field. We derive generalized rate equations for the dot's occupation and accumulated spin and discuss the influence of the dot's spin on the transmission. A negative differential conductance and a nontrivial dependence of the conductance on the angle between the lead magnetizations is predicted.