Electric-field control of skyrmions in multiferroic heterostructure via magnetoelectric coupling

You Ba,Ying Zhang,Huanfang Tian,Jia-Mian Hu,Haifeng Du,Mingfeng Chen,Wanjun Jiang,Hengan Zhou,Quan Liu,Yonggang Zhao,Cewen Nan,Guozhi Chai,Yutong Wang,Shihao Zhuang,Yang Gao,Weideng Sun,Jing Ma,Yike Zhang

doi:10.1038/s41467-020-20528-y

Abstract

Room-temperature skyrmions in magnetic multilayers are considered to be promising candidates for the next-generation spintronic devices. Several approaches have been developed to control skyrmions, but they either cause significant heat dissipation or require ultrahigh electric fields near the breakdown threshold. Here, we demonstrate electric-field control of skyrmions through strain-mediated magnetoelectric coupling in ferromagnetic/ferroelectric multiferroic heterostructures. We show the process of non-volatile creation of multiple skyrmions, reversible deformation and annihilation of a single skyrmion by performing magnetic force microscopy with in situ electric fields. Strain-induced changes in perpendicular magnetic anisotropy and interfacial Dzyaloshinskii–Moriya interaction strength are characterized experimentally. These experimental results, together with micromagnetic simulations, demonstrate that strain-mediated magnetoelectric coupling (via strain-induced changes in both the perpendicular magnetic anisotropy and interfacial Dzyaloshinskii–Moriya interaction is responsible for the observed electric-field control of skyrmions. Our work provides a platform to investigate electric-field control of skyrmions in multiferroic heterostructures and paves the way towards more energy-efficient skyrmion-based spintronics.

Highlights

Room-temperature skyrmions in magnetic multilayers are considered to be promising candidates for the next-generation spintronic devices
Ta(4.7 nm)/[Pt(4 nm)/Co(1.6 nm)/Ta(1.9 nm)] × 5 multilayers were deposited by using ultrahigh vacuum magnetron sputtering on PMN-PT(001) single-crystal substrate, and separately on a 30-nm-thick Si3N4 membrane for Lorentz transmission electron microscopy (L-TEM) observation
The stack structure and setup for magnetic force microscopy (MFM) measurement with in situ electric fields are schematically shown in Supplementary Fig. 1

Summary

Introduction

Room-temperature skyrmions in magnetic multilayers are considered to be promising candidates for the next-generation spintronic devices. We demonstrate electric-field control of skyrmions through strain-mediated magnetoelectric coupling in ferromagnetic/ferroelectric multiferroic heterostructures. Strain-mediated electric-field control of magnetism in multiferroic heterostructure consisting of FM and ferroelectric layers has been widely studied[23,24,25]. In contrast to electric-field gating, electric-field-induced strains in the ferroelectric can be transferred to the FM layer over hundreds of nanometers[26] or more, which should lead to a more effective skyrmion manipulation by modulating both the magnetic anisotropy and the interfacial DMI of the HM/FM interface. We demonstrate strain-mediated electric-field control of skyrmions through magnetoelectric coupling in multiferroic heterostructure composed of [Pt/Co/Ta] × 5 magnetic multilayer and ferroelectric Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (PMN-PT). Our findings will stimulate more research for electric-field control of skyrmions in multiferroic heterostructures, with application to skyrmion-based low-power spintronic devices

Methods

Results

Conclusion