Giant tunneling magnetoresistance based on spin-valley-mismatched ferromagnetic metals

TL;DR

This paper introduces a new class of spin-valley-mismatched metals that enable giant tunneling magnetoresistance in van der Waals junctions, expanding possibilities for high-performance spintronic devices.

Contribution

It demonstrates that materials with intrinsic spin-valley mismatch can achieve near 100% magnetoresistance, offering a novel approach to high-magnetoresistance device design.

Findings

Giant magnetoresistance of over 99% achieved in vdW junctions.

Identification of ferromagnetic 1T-VSe2, 1T-VS2, and 2H-VS2 as spin-valley-mismatched metals.

Intrinsic spin-valley mismatch enables arbitrary nonmagnetic materials as the central layer.

Abstract

Half metals, which are amenable to perfect spin filtering, can be utilized for high-magnetoresistive devices. However, available half metals are very limited. Here, we demonstrate that materials with intrinsic spin-valley-mismatched (SVM) states can be used to block charge transport, resembling half metals and leading to giant tunneling magnetoresistance. As an example, by using first-principles transport calculations, we show that ferromagnetic 1\emph{T}-VSe$_2$, 1\emph{T}-VS$_2$, and 2\emph{H}-VS$_2$ are such spin-valley-mismatched metals, and giant magnetoresistance of more than 99\% can be realized in spin-valve van der Waals (vdW) junctions using these metals as electrodes. Owing to the intrinsic mismatch of spin states, the central-layer materials for the vdW junctions can be arbitrary nonmagnetic materials, in principle. Our research provides clear physical insights into the mechanism for high magnetoresistance and opens new avenues for the search and design of high-magnetoresistance devices.