Creating and Deleting a Single Dipolar Skyrmion by Surface Spin Twists

TL;DR

This paper demonstrates deterministic creation and deletion of single dipolar skyrmions in nanostructured cuboids using in-plane currents, enabling reliable single-bit operations for skyrmionic devices.

Contribution

It introduces a method for reversible skyrmion writing and deleting without defects, based on spin-transfer torque on surface spin twists, supported by micromagnetic simulations.

Findings

Successful deterministic skyrmion creation and deletion.

Reversible operations without artificial defects.

Consistent simulation results confirming the mechanism.

Abstract

We report deterministic operations on single dipolar skyrmions confined in nanostructured cuboids using in-plane currents. We achieve highly reversible writing and deleting of skyrmions in the simple cuboid without any artificial defects or pinning sites. The current-induced creation of skyrmions is well-understood through the spin-transfer torque acting on surface spin twists of the spontaneous 3D ferromagnetic state, caused by the magnetic dipole-dipole interaction of the uniaxial Fe3Sn2 magnet with a low-quality factor. Current-induced deletions of skyrmions result from the combined effects of magnetic hysteresis and Joule thermal heating. Our results are replicated consistently through 3D micromagnetic simulations. Our approach offers a viable method for achieving reliable single-bit operations in skyrmionic devices for applications such as random-access memories.