Quenching of an antiferromagnet into high resistivity states using electrical or ultrashort optical pulses

TL;DR

This paper demonstrates reversible switching of an antiferromagnetic CuMnAs film into high resistivity states using electrical or ultrashort optical pulses, with potential applications in spintronics and neuromorphic devices.

Contribution

It introduces a method to quench antiferromagnetic states into nano-fragmented domains with significant resistivity changes, enabling optical readout and neuromorphic functionalities.

Findings

Resistivity changes up to 20% at room temperature.

Reversible and reproducible switching into nano-domains.

Optical reflectivity can be used for readout.

Abstract

Ultra-fast dynamics, insensitivity to external magnetic fields, or absence of magnetic stray fields are examples of properties that make antiferromagnets of potential use in the development of spintronic devices. Similar to their ferromagnetic counterparts, antiferromagnets can store information in the orientations of the collective magnetic order vector. However, also in analogy to ferromagnets, the readout magnetoresistivity signals in simple antiferromagnetic films have been weak and the extension of the electrical reorientation mechanism to optics has not been achieved. Here we report reversible and reproducible quenching of an antiferromagnetic CuMnAs film by either electrical or ultrashort optical pulses into nano-fragmented domain states. The resulting resistivity changes approach 20\% at room temperature, which is comparable to the giant magnetoresistance ratios in ferromagnetic multilayers. We also obtain a signal readout by optical reflectivity. The analog time-dependent switching and relaxation characteristics of our devices can mimic functionality of spiking neural network components.