Field‐Free Manipulation of Skyrmion Creation and Annihilation by Tunable Strain Engineering

Abstract

AbstractCreation and annihilation of skyrmions are two crucial issues for constructing skyrmion‐based memory and logic devices. To date, these operations were mainly achieved by means of external magnetic, electrical, and optical modulations. In this work, we demonstrated an effective strain‐induced skyrmion nucleation/annihilation phenomenon in [Pt/Co/Ta]n multilayers utilizing the shape memory effect of a TiNiNb substrate. A tunable tensile strain up to 1.0% can be realized in the films by thermally driving phase transition of the substrate, which significantly decreases the nucleation field of skyrmions by as many as 400 Oe and facilitates the field‐free manipulation of skyrmions with the strain. Such a strain effect can be attributed to the synergetic interplay of the planar magnetic moment twirling and decrement of interfacial Dzyaloshinskii–Moriya interaction. In addition, the strain tunability is found to be strongly related to the strain direction due to magnetoelastic interaction. These findings provide a novel strategy for developing strain‐assisted skyrmion‐based memory and logic devices.