Resonant tunneling magnetoresistance in epitaxial metal-semiconductor heterostructures

TL;DR

This paper demonstrates resonant tunneling magnetoresistance in epitaxial metal-semiconductor heterostructures, showing how localized states influence spin polarization and magnetoresistance sign, with implications for spintronic device control.

Contribution

It reveals the impact of localized states on resonant tunneling magnetoresistance and how bias voltage and symmetry can reverse the magnetoresistance sign in epitaxial heterostructures.

Findings

Magnetoresistance sign can be reversed by bias voltage.

Localized states significantly affect tunneling magnetoresistance.

Resonant conditions lead to strong averaging effects that diminish magnetoresistance.

Abstract

We report on resonant tunneling magnetoresistance via localized states through a ZnSe semiconducting barrier which can reverse the sign of the effective spin polarization of tunneling electrons. Experiments performed on Fe/ZnSe/Fe planar junctions have shown that positive, negative or even its sign-reversible magnetoresistance can be obtained, depending on the bias voltage, the energy of localized states in the ZnSe barrier and spatial symmetry. The averaging of conduction over all localized states in a junction under resonant condition is strongly detrimental to the magnetoresistance.