Propagation of Spin-Polarized Electrons Through Interfaces Separating Differently Doped Semiconductor Regions

TL;DR

This paper investigates how spin-polarized electrons propagate across boundaries between differently doped semiconductors, showing that spin polarization can be compressed and amplified without significant loss, aiding spintronic device design.

Contribution

It introduces a model for spin-polarized electron transport across doping boundaries, demonstrating potential for spin polarization amplification without interface loss.

Findings

Spin polarization can be compressed and amplified near doping boundaries.

No significant spin loss occurs at doping boundaries without material interfaces.

The model aids in designing improved spintronic devices.

Abstract

High degree of electron spin polarization is of crucial importance in operation of spintronic devices. We study the propagation of spin-polarized electrons through a boundary between two n-type semiconductor regions with different doping levels. We assume that inhomogeneous spin polarization is created/injected locally and driven through the boundary by the electric field. The electric field distribution and spin polarization distribution are calculated within a two-component drift-diffusion transport model. We show that an initially created narrow region of spin polarization can be further compressed and amplified near the boundary. Since the boundary involves variation of doping but no real interface between two semiconductor materials, no significant spin-polarization loss is expected. The proposed mechanism will be therefore useful in designing new spintronic devices.