Spin-dependent tunneling in the nearly-free-electron model

TL;DR

This paper investigates spin-dependent tunneling using a nearly-free-electron model, highlighting the influence of band gaps and bias on transport properties, and extending the analysis to ferromagnetic leads to explore tunnel magneto-resistance.

Contribution

It introduces a nearly-free-electron approach to model spin-dependent tunneling, providing insights into bias effects and magneto-resistance in ferromagnetic systems.

Findings

Band gaps significantly affect tunneling behavior.

Bias dependence of tunnel magneto-resistance is characterized.

Comparison with free-electron models highlights key differences.

Abstract

Spin-dependent ballistic transport through a tunnel barrier is treated within the one-dimensional nearly-free-electron model. The comparison with free electrons reveals significant effects of band gaps, in particular in the bias dependence. The results are qualitatively explained by the number of incident and transmitted states in the leads. With an extension to ferromagnetic leads the bias dependence of tunnel magneto-resistance is discussed.