Executive Summary : | Non-collinear spin textures such as magnetic domain walls, magnetic vortices, magnetic skyrmions, and antiskyrmions are considered promising candidates for potential memory and logic devices applications in spintronics. Specifically, the magnetic skyrmion has been widely investigated due to its novel static and dynamic magnetic properties and its technological implications in information storage and processing devices. Skyrmions are particle-like magnetic configurations as small as a few nanometers, and they are topologically stable. Skyrmions can be moved by very small currents (~100 A/cm²). These properties make it a promising information carrier for real-device applications. To realize and stabilize skyrmions in thin layered films, intrinsic Dzyaloshinskii–Moriya interaction (DMI) supporting non-collinear spin textures and strong spin-orbit interaction at the interfaces of the layered films is indispensable. Since the strength of DMI is not very strong in planar thin films, investigation of alternate systems wherein skyrmions are further stabilized is exciting. Recent theoretical studies show that introducing curvature in thin films is an effective way to stabilize skyrmions even in non-DMI systems. It has been reported that the curvature-induced DMI has a constructive role in stabilizing skyrmions. It was found that a localized curvilinear defect can enhance the stabilization of skyrmion formations in perpendicularly magnetized ferromagnetic thin films. In particular, magnetic skyrmions are predicted to be stabilized in a spherical shell by the curvature effect even without DMI. Thus, the combination of effective anisotropy of thin-film and the curvature induced DMI could make possible significant modulations in the stability as well as the static and dynamical magnetic properties of skyrmions in geometrically curved systems, even without intrinsic Dzyaloshinskii–Moriya interaction. Here, we propose to demonstrate experimentally that curved geometric confinement is another effective way to stabilize the topological configuration of a skyrmion with the help of magnetic anisotropy. Further, we propose a deeper insight into the curvature stabilized skyrmions via micromagnetic simulations. Specific objectives of this proposal are: 1. Realization of skyrmions in hemispherical nanocap geometries. 2. Investigating the stabilization of the skyrmion phase with the diameter (curvature) of the nanocaps. 3. Obtaining a correlation between the static magnetic properties of the skyrmions and the geometrical curvature. We expect the findings to provide a deep insight into skyrmion stability in curved architectures without DMI and offer an effective means of tailoring the skyrmion properties for device applications. By combining self-assembly technique with magnetic thin film deposition, the proposed project will provide a new means of stabilisation of skyrmions in closely packed arrays of magnetic nanostructures. |