Electric field control of deterministic current-induced magnetization switching in a hybrid ferromagnetic/ferroelectric structure

TL;DR

This paper demonstrates electric field-induced deterministic magnetization switching in a hybrid ferromagnetic/ferroelectric structure, replacing external magnetic fields with electrically controlled effective magnetic fields for low-energy magnetic memory applications.

Contribution

It introduces a method to induce and reverse an in-plane effective magnetic field via electric fields in a ferromagnetic/ferroelectric structure, enabling deterministic switching without external magnetic fields.

Findings

Electric field induces an effective magnetic field in the structure.

Reversal of the effective magnetic field is achieved by changing electric field direction.

Electric field generates additional spin-orbit torque confirmed by macrospin calculations.

Abstract

All-electrical and programmable manipulations of ferromagnetic bits are highly pursued for the aim of high integration and low energy consumption in modern information technology. Methods based on the spin-orbit torque switching in heavy metal/ferromagnet structures have been proposed with magnetic field, and recently are heading toward deterministic switching without external magnetic field. Here we demonstrate that an in-plane effective magnetic field can be induced by an electric field without breaking the symmetry of the structure of the thin film, and realize the deterministic magnetization switching in a hybrid ferromagnetic/ferroelectric structure with Pt/Co/Ni/Co/Pt layers on PMN-PT substrate. The effective magnetic field can be reversed by changing the direction of the applied electric field on the PMN-PT substrate, which fully replaces the controllability function of the external magnetic field. The electric field is found to generate an additional spin-orbit torque on the CoNiCo magnets, which is confirmed by macrospin calculations.