Spin filtering in a hybrid ferromagnetic-semiconductor microstructure

TL;DR

This study demonstrates spin filtering in a hybrid ferromagnetic-semiconductor microstructure, revealing spin-dependent transport effects influenced by magnetic field and electron density.

Contribution

It introduces a novel hybrid structure with local spin-dependent potential barriers and analyzes spin effects in ballistic transport at low magnetic fields.

Findings

Spin effects observed in ballistic transport at tens of millitesla.

Switching between Zeeman and Stern-Gerlach modes influences spin filtering.

Spin filtering is tunable by magnetic field and electron density.

Abstract

We fabricated a hybrid structure in which cobalt and permalloy micromagnets produce a local in-plane spin-dependent potential barrier for high-mobility electrons at the GaAs/AlGaAs interface. Spin effects are observed in ballistic transport in the tens' millitesla range of the external field, and are attributed to switching between Zeeman and Stern-Gerlach modes -- the former dominating at low electron densities.