Controlling spin-orbit torque by polarization field in multiferroic BiFeO3 based heterostructures

TL;DR

This study demonstrates how polarization fields in BiFeO3-based heterostructures can effectively control spin-orbit torque, enabling tunable magnetization switching for advanced spintronic applications.

Contribution

It introduces a novel method to modulate switching current density via polarization control in multiferroic heterostructures, with significant changes in magnetic properties and spin Hall angles.

Findings

Polarization fields significantly alter magnetic anisotropy and SOT-induced switching.

Effective spin Hall angles vary by 272% with opposite polarizations.

Potential applications demonstrated in memory and reconfigurable logic devices.

Abstract

In the last few years, some ideas of electric manipulations in ferromagnetic heterostructures have been proposed for developing next generation spintronic devices. Among them, the magnetization switching driven by spin-orbit torque (SOT) is being intensely pursued. Especially, how to control the switching current density, which is expected to enrich device functionalities, has aroused much interest among researchers all over the world. In this paper, a novel method to adjust the switching current is proposed, and the BiFeO3 (BFO) based heterostructures with opposite spontaneous polarizations fields show huge changes in both perpendicular magnetic anisotropy and the SOT-induced magnetization switching. The damping-like torques were estimated by using harmonic Hall voltage measurement, and the variation of effective spin Hall angles for the heterostructures with opposite polarizations was calculated to be 272%. At the end of this paper, we have also demonstrated the possible applications of our structure in memory and reconfigurable logic devices.