Antisymmetric magnetoresistance in magnetic multilayers with perpendicular anisotropy

TL;DR

This paper reports the discovery of antisymmetric magnetoresistance in Co/Pt multilayers with perpendicular anisotropy, attributed to domain wall effects and the extraordinary Hall effect, supported by experimental and theoretical analysis.

Contribution

It introduces a novel antisymmetric MR phenomenon in perpendicular magnetic multilayers and provides a quantitative theoretical explanation for it.

Findings

Antisymmetric MR observed in Co/Pt multilayers.

Domain walls induce circulating currents affecting MR.

Theoretical model successfully explains the antisymmetric MR.

Abstract

While magnetoresistance (MR) has generally been found to be symmetric in applied field in non-magnetic or magnetic metals, we have observed antisymmetric MR in Co/Pt multilayers. Simultaneous domain imaging and transport measurements show that the antisymmetric MR is due to the appearance of domain walls that run perpendicular to both the magnetization and the current, a geometry existing only in materials with perpendicular magnetic anisotropy. As a result, the extraordinary Hall effect (EHE) gives rise to circulating currents in the vicinity of the domain walls that contributes to the MR. The antisymmetric MR and EHE have been quantitatively accounted for by a theoretical model.