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

Abstract

Creation 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.

Progress in magnetic alloys with kagome structure: materials, fabrications and physical properties

“…The quest for materials that host topologically protected nano-metric spin textures, so-called magnetic skyrmions or magnetic skyrmion bubbles, continues to be fueled by the promise of novel devices. 1 Skyrmionic spin textures have mostly been observed in noncentrosymmetric crystals, such as MnSi, 2,3 FeGe, 4 FeCoSi, 5 Cu 2 OSeO 3 , 6 GaV 4 S 8 , 7 Pt/Co/Ta 8–11 and Pt/Co/Ta/MgO/CoFeB/Mo, 12 where the Dzyaloshinskii–Moriya interaction (DMI) is active. 7 In addition to noncentrosymmetric chiral magnets in which magnetic skyrmions are stabilized by the DMI, centrosymmetric materials with uniaxial magnetic anisotropy (UMA) are another family of materials that can host skyrmions.…”

Perspective on skyrmion spintronics

“…Initial studies have expanded this concept towards active anisotropy control via strain engineering (in this instance via temperature). This is an exciting first step towards developing strain-assisted skyrmion-based memory and logic devices 57 . Strain manipulation is an innovative solutions for devices of the future which reduces energy dissipation and the risk of heightened temperatures within the device caused by current pulses 58 .…”

Local Manipulation of Skyrmion Nucleation in Microscale Areas of a Thin Film with Nitrogen-Ion Implantation

“…In addition to the charge or spin attribute, the crystal lattice provides another degree of freedom to modify the magnetic interactions. In previous studies, strain was the conventional scheme to tune the lattice attribute, and it could induce obvious modifications on both the DMI and magnetic anisotropy of skyrmion-hosting films based on the magnetoelastic effect. − However, the application of strain on the films required a stretchable substrate (e.g., ferroelectrics, shape memory alloy, and flexible polymer), posing a great challenge concerning compatibility with modern large-scale integrated circuit technology (LSICT). An alternative strategy for lattice modification is to introduce lattice defects (e.g., vacancies and interstitials), which have been demonstrated to be able to significantly affect the Heisenberg exchange interaction, magnetic anisotropy, and DMI. − Thus, the skyrmion nucleation is expected to be controllably manipulated through appropriate defect engineering.…”