Antiferromagnetic coupling across silicon regulated by tunneling currents

TL;DR

This paper demonstrates that voltage-driven tunneling currents can significantly enhance antiferromagnetic coupling in Fe/Si/Fe structures, with implications for spintronic device control at room temperature.

Contribution

It reveals how tunneling currents can be used to control and stabilize antiferromagnetic coupling via local spin torques, a novel approach in spintronics.

Findings

Magnetocurrent exceeds 200% at room temperature.

Antiferromagnetic coupling is stabilized and increased by tunneling currents.

Magnetic field required for parallel alignment rises with tunneling current.

Abstract

We report on the enhancement of antiferromagnetic coupling in epitaxial Fe/Si/Fe structures by voltage-driven spin-polarized tunneling currents. Using the ballistic electron magnetic microscopy we established that the hot-electron collector current reflects magnetization alignment and the magnetocurrent exceeds 200% at room temperature. The saturation magnetic field for collector current corresponding to parallel alignment of magnetizations rises up with the tunneling current, thus demonstrating stabilization of the antiparallel alignment and increasing antiferromagnetic coupling. We connect the enhancement of antiferromagnetic coupling with local dynamic spin torques mediated by tunneling electrons