Spin dynamics of strain induced topological antiferromagnetic spin textures in thin film canted antiferromagnet hematite (α-Fe2O3)

Abstract

Topological spin textures are considered promising candidates for beyond-CMOS computing and memory applications. The canted antiferromagnet α-Fe2O3 (hematite), provides a unique platform for novel magnonic devices due to its low magnetic damping and fast spin waves (SW). Spin textures such as half-skyrmions and bimerons are reported in thin films of hematite. Here, we report inelastic Brillouin light scattering measurement on GHz SWs in high-quality thin films of hematite. Measured spectra show several modes and irregular frequency jumps at low field values. The observed frequencies exhibits strong spatial dependency including localized SWs at a given eigen frequency and field. Assuming a spatial distribution of strain in the thin film which results from the substrate clamping and intrinsic magnetostriction effect, we solve the coupled magnetoelastodynamics equations. Our micromagnetic simulations unravel the underlying mechanism of noncollinear spin texture formation as well as spatially non-uniform SW frequencies. Our results provide a fundamental understanding of the origin of the non-collinear textures and their spin dynamics observed in hematite thin films.