Magnetic Skyrmion Deformation Driven by High-frequency Dynamic Perpendicular Magnetic Anisotropy Variation in a Confined Nanostructure

Abstract

Skyrmion-based nano-oscillators and race-track memory are two examples of contemporary spintronic-based device technologies that show promise due to magnetic skyrmions. Specifically, skyrmion intrinsic modes related to shape deformation are activated, which is important, particularly for microwave-generating devices. Here, we report the excitation of skyrmion internal modes within a nanodisc by the dynamic perpendicular magnetic anisotropy (PMA) and obtained the shape deformation of skyrmion, characterized by integer n with values 2, 3 and 4 for elliptic, triangular and quadrilateral instabilities, respectively, at higher resonance frequencies (> 60 Hz) for different PMA excitation amplitudes varying from 0.01 to 0.1 MJ/m³. Using the domain wall (DW) ansatz model, we examined the deformation of the skyrmion shape caused by the activation of internal modes. In the field of designing next-generation energy-efficient skyrmion-based microwave detectors and nano-oscillators, these results can help obtain the basic physics behind the skyrmion deformation associated with the internal modes within a wide range of resonance frequencies and enhance skyrmion-based device performance by enabling precise control over resonance frequencies and shape deformation, potentially improving energy efficiency, sensitivity, and bandwidth, with up to 20-30% improvements in frequency tunability and power efficiency.