Spin Injection in a Ballistic Two-Dimensional Electron Gas

TL;DR

This paper investigates spin-polarized transport in a ballistic 2D electron gas, demonstrating clear signatures of spin precession effects influenced by device geometry, with implications for spin transistor technology.

Contribution

It introduces a realistic model for spin-selective contacts in ballistic transport, highlighting geometry-dependent spin precession effects absent in diffusive regimes.

Findings

Signatures of spin transport are clearly observed.

Spin precession effects depend strongly on device geometry.

Effects vanish in the diffusive limit.

Abstract

We explore electrically injected, spin polarized transport in a ballistic two-dimensional electron gas. We augment the Buettiker-Landauer picture with a simple, but realistic model for spin-selective contacts to describe multimode reservoir-to-reservoir transport of ballistic spin 1/2 particles. Clear and unambiguous signatures of spin transport are established in this regime, for the simplest measurement configuration that demonstrates them directly. These new effects originate from spin precession of ballistic carriers; they exhibit strong dependence upon device geometry and vanish in the diffusive limit. Our results have important implications for prospective ``spin transistor'' devices.