Large anomalous Hall effect and anisotropic magnetoresistance in intrinsic nanoscale spin-valve-type structure of an antiferromagnet

TL;DR

This paper demonstrates intrinsic nanoscale spin-valve behavior in an antiferromagnetic material, showing large anomalous Hall effects and anisotropic magnetoresistance driven by spin-flips, advancing antiferromagnetic spintronics.

Contribution

It introduces a novel antiferromagnetic spin-valve structure with embedded spin stacks and explores its magnetic and transport properties under rotating magnetic fields.

Findings

Large anomalous Hall conductivity observed.

Anisotropic magnetoresistance maximized above spin-flip transition.

Experimental and theoretical analysis enables spin state readout.

Abstract

A spin valve is a prototype of spin-based electronic devices found on ferromagnets, in which an antiferromagnet plays a supporting role. Recent findings in antiferromagnetic spintronics show that an antiferromagnetic order in single-phase materials solely governs dynamic transport, and antiferromagnets are considered promising candidates for spintronic technology. In this work, we demonstrated antiferromagnet-based spintronic functionality on an itinerant Ising antiferromagnet of Ca0.9Sr0.1Co2As2 by integrating nanoscale spin-valve-type structure and investigating anisotropic magnetic properties driven by spin-flips. Multiple stacks of 1 nm thick spin-valve-like unit are intrinsically embedded in the antiferromagnetic spin structure. In the presence of a rotating magnetic field, a new type of the spin-valve-like operation was observed for large anomalous Hall conductivity and anisotropic magnetoresistance, whose effects are maximized above the spin-flip transition. In addition, a joint experimental and theoretical study provides an efficient tool to read out various spin states, which scheme can be useful for implementing extensive spintronic applications.