Electrical Detection of Spin Accumulation at a Ferromagnet-Semiconductor Interface

TL;DR

This paper demonstrates electrical detection of spin accumulation at a ferromagnet-semiconductor interface, showing how spin polarization affects voltage signals and can be controlled by magnetic fields, bias, and temperature.

Contribution

It provides experimental evidence and a theoretical model for electrical detection of spin accumulation at Fe/n-GaAs interfaces, advancing spintronic measurement techniques.

Findings

Spin accumulation causes measurable voltage drops.

Magnetic fields suppress the spin-induced voltage signal.

The results agree with drift-diffusion spin transport models.

Abstract

We show that the accumulation of spin-polarized electrons at a forward-biased Schottky tunnel barrier between Fe and n-GaAs can be detected electrically. The spin accumulation leads to an additional voltage drop across the barrier that is suppressed by a small transverse magnetic field, which depolarizes the spins in the semiconductor. The dependence of the electrical accumulation signal on magnetic field, bias current, and temperature is in good agreement with the predictions of a drift-diffusion model for spin-polarized transport.