Tailoring bimeron-antibimeron in Permalloy submicron dot via field–induced magnetization reversal

Abstract

The controlled nucleation and manipulation of topological spin textures such as bimerons and antibimerons, remain significant challenges for advancing spintronic technologies. We investigate the tunable controllability and selective manipulation of bimeron and antibimeron pairs in two thicknesses (t = 2 and 4 nm) of Py sub-micron dot systems using magnetization reversal investigation in micromagnetic simulations. By systematically varying material parameters such as the Dzyaloshinskii–Moriya interaction (DMI) constant, dot thickness, and applying external bias fields, we demonstrate control over the nucleation, stability, and annihilation of bimeron-antibimeron pairs. Our results reveal that the size of the bimeron–antibimeron pair approximately reduces from 23 to 19 nm when the thickness of the dot is increased from 2 to 4 nm. It is also seen that the spatial separation of bimeron pairs is strongly dependent on the dot thickness. Notably, the selective stabilization of either bimerons or antibimerons can be achieved by adjusting the sign and magnitude of the DMI constant (D = ±3.0 mJ/m²). Finally, the application of suitable bias fields during magnetization reversal enables additional selectivity in controlling these topological spin textures. These findings provide new insights into the engineering and manipulation of topologically protected bimerons-antibimerons spin textures, highlighting their potential for future spintronic device applications.