Physics Origin of Universal Unusual Magnetoresistance

TL;DR

This paper reveals that the universal unusual magnetoresistance (UMR) can originate from electron scattering mechanisms independent of spin current, unifying various magnetoresistance phenomena under a two-vector model.

Contribution

It introduces a new two-vector magnetoresistance theory that explains UMR without relying on spin current, challenging previous spin-current-based explanations.

Findings

Giant UMR observed in single-layer magnetic metals.

High-order contributions and a universal sum rule identified.

Literature data reinterpreted under the two-vector MR framework.

Abstract

The discovery of the unusual magnetoresistance (UMR) during the rotation of magnetization in the plane perpendicular to the electric current, which has been typically attributed to magnetization-dependent interfacial reflection of spin current, has brought remarkable impacts on the understanding and application of a variety of spintronic phenomena. Here, we report that giant UMR occurs also in single-layer magnetic metals and exhibits high-order contributions and a universal sum rule, which agree well with the physics origin of the recently proposed two-vector magnetoresistance that simply considers electron scattering by the magnetization vector and interfacial electric field, without the need for any relevance to spin current. Revisiting of the literature data reveals that the most representative data that were used to claim spin Hall magnetoresistance or other magnetoresistances related or unrelated to spin current can be understood unifiedly by the two-vector MR theory. Experimental and theoretical results against spin-current-related magnetoresistances, but not the two-vector magnetoresistance, are discussed.