Stabilization of the skyrmion in a hybrid magnetic-superconducting nanostucture

TL;DR

This paper proposes using superconducting nanorings to generate inhomogeneous magnetic fields that stabilize Neel skyrmions in ferromagnetic layers, combining analytical and micromagnetic methods.

Contribution

It introduces a novel method of stabilizing skyrmions via superconducting currents, expanding control over skyrmion stability without Dzyaloshinskii-Moriya interaction.

Findings

Superconducting currents above a critical value stabilize skyrmions.

The stabilization depends on nanoring size and induced current.

Analytical and micromagnetic results agree for different magnetic films.

Abstract

Stabilization of skyrmions in a magnetic material without the Dzyaloshinskii-Moriya exchange interaction requires using of an inhomogeneous magnetic field, such as a demagnetization field or an Oersted field. To control and tune the local magnetic field in magnetic material we propose to exploit superconducting nanorings. The field stabilizes the skyrmion through the presence of persistent current induced by the pulses of external field. We analyze the conditions for the stabilization of Neel skyrmion in ferromagnetic layers with out-of-plane anisotropy, as a function of the nanoring size and induced superconducting current. We show that the superconducting current should exceed a critical value for the skyrmion to become stable. The paper presents consistent results from both analytical and micromagnetic calculations for Co and Ga:YIG thin magnetic films.