Uncovering the skyrmion bubble magnetic states in centrosymmetric kagome magnet Mn4Ga2Sn

Abstract

The successful realization of skyrmion based next generation spintronic devices greatly depends on the easy manipulation of underlying magnetic interactions in the skyrmion hosting materials. In this direction, although the mechanism of skyrmion formation in non-centrosymmetric magnets is comprehensively established, contradicting views on the stabilization process of skyrmion/bubble magnetic states in centrosymmetric magnets need further investigation. Here, we report the finding of a tunable skyrmion lattice up to room temperature in a new skyrmion hosting centrosymmetric kagome ferromagnet Mn4Ga2Sn. Using an extensive Lorentz transmission electron microscopy experiment at different temperatures, we demonstrate that both the Bloch-type skyrmions and type-II magnetic bubbles can be stabilized depending upon the nature of magnetic field excitation and strength of uniaxial magnetic anisotropy in the system. Most importantly, we illustrate a controlled switching between the topological skyrmions and the non-topological type-II magnetic bubbles by applying a small in-plane magnetic field. Our results categorically establish that the topological Bloch-type skyrmions are the energetically most stable magnetic objects in the centrosymmetric hexagonal magnets, whereas the type-II magnetic bubbles, instead of biskyrmions, are the excited magnetic states in the system. The present study is an important step towards the basic understanding of the skyrmion stabilization mechanism in centrosymmetric materials and paves the way for their future application in spintronics.

Skyrmion fluid and bimeron glass protected by a chiral spin liquid on a kagome lattice

“…5 and video S3]. These one-dimensional textures are sometimes referred to as "snakes" in the literature [45][46][47]. Once nucleated, the growth of bimerons in this field regime is almost instantaneous in our simulations, occupying the empty space between pre-existing skyrmions.…”