The effects of Mn concentration on spin-polarized transport through ZnSe/ZnMnSe/ZnSe heterostructures

TL;DR

This study investigates how Mn concentration influences spin-polarized transport in ZnSe/ZnMnSe/ZnSe heterostructures, demonstrating tunable spin polarization and potential for spin filter applications.

Contribution

It introduces a model linking Mn concentration to spin transport properties, enabling control over spin polarization in magnetic semiconductor heterostructures.

Findings

Spin current density depends strongly on Mn concentration.

Electron-spin polarization and tunnel magnetoresistance can be tuned by Mn levels.

Achieves 100% spin polarization, enabling spin filter devices.

Abstract

We have studied the effects of Mn concentration on the ballistic spin-polarized transport through diluted magnetic semiconductor heterostructures with a single paramagnetic layer. Using a fitted function for zero-field conduction band offset based on the experimental data, we found that the spin current densities strongly depend on the Mn concentration. The magnitude as well as the sign of the electron-spin polarization and the tunnel magnetoresistance can be tuned by varying the Mn concentration, the width of the paramagnetic layer, and the external magnetic field. By an appropriate choice of the Mn concentration and the width of the paramagnetic layer, the degree of spin polarization for the output current can reach 100% and the device can be used as a spin filter.