Magnetoelectric memory function with optical readout

TL;DR

This paper demonstrates optical readout of magnetoelectric memory states in LiCoPO4, leveraging the dynamic ME effect of spin-wave excitations, paving the way for low-power, non-volatile memory devices based on antiferroelectric-antiferromagnetic insulators.

Contribution

It introduces a novel optical readout method for ME memory states in LiCoPO4, supported by a microscopic model, advancing the development of future ME memory devices.

Findings

Strong THz absorption difference between ME domains enables optical readout.

Microscopic model confirms the dynamic ME effect causes the absorption contrast.

Proof-of-principle demonstrates control and detection of ME domains optically.

Abstract

The ultimate goal of multiferroic research is the development of new-generation non-volatile memory devices, the so-called magnetoelectric (ME) memories, where magnetic bits are controlled via electric fields without the application of electrical currents subject to dissipation. This low-power operation exploits the entanglement of the magnetization and the electric polarization coexisting in multiferroic materials. Here we demonstrate the optical readout of ME memory states in the antiferromagnetic (AFM) and antiferroelectric (AFE) LiCoPO$_4$, based on the strong absorption difference of THz radiation between its two types of ME domains. This unusual contrast is attributed to the dynamic ME effect of the spin-wave excitations, as confirmed by our microscopic model, which also captures the characteristics of the observed static ME effect. Our proof-of-principle study, demonstrating the control and the optical readout of ME domains in LiCoPO$_4$, lays down the foundation for future ME memory devices based on antiferroelectric-antiferromagnetic insulators.