Spin blocker made of semiconductor double quantum well using the Rashba effect

TL;DR

This paper proposes a semiconductor double quantum well device utilizing the Rashba effect to achieve spin blockade, enabling spin-polarized current generation for spintronics.

Contribution

It introduces a novel lateral spin-blockade device using InGaAs/InAlAs double quantum wells with opposite Rashba parameters, demonstrating controllable spin filtering.

Findings

Achieves spin blockade by wave vector matching of spin-split Fermi surfaces.

Enables tunable spin-polarized current through device parameter adjustments.

Provides a new approach for spintronics based on band engineering.

Abstract

We propose a lateral spin-blockade device that uses an InGaAs/InAlAs double quantum well (DQW), where the values of the Rashba spin-orbit parameter $\alpha_{\rm R}$ are opposite in sign but equal in magnitude between the constituent quantum wells (QW). By tuning the channel length of DQW and the magnitude of the externally applied in-plane magnetic field, one can block the transmission of one spin (e.g., spin-down) component, leading to a spin-polarized current. Such a spin-blocking effect, brought about by wave vector matching of the spin-split Fermi surfaces between the two QWs, paves the way for a new scheme of spin-polarized electric current generation for future spintronics applications based on semiconductor band engineering.