Quantum Collapse of a Magnetic Skyrmion

TL;DR

This paper investigates the quantum tunneling-induced collapse of small magnetic skyrmions in thin films, analyzing stability conditions, deriving dynamics, and calculating tunneling rates to understand their quantum decay behavior.

Contribution

It provides an analytical and numerical study of the quantum collapse mechanism of skyrmions, including the derivation of the coupled dynamics and tunneling rate calculations.

Findings

Identified the conditions for skyrmion quantum collapse.

Derived equations of motion with instanton solutions.

Computed the tunneling rate for skyrmion decay.

Abstract

Quantum collapse of a small skyrmion in a thin magnetic film with Dzyalishinskii-Moriya (DMI) interaction has been studied. The energy of the skyrmion and the stability threshold determined by the DMI, the external magnetic field, and the underlying atomic lattice are investigated analytically and numerically. The Lagrangian describing the coupled dynamics of the skyrmion size and the chirality angle is derived. Equations of motion possess an instanton solution that corresponds to the skyrmion underbarrier contraction via quantum tunneling with subsequent collapse and decay of the topological charge. The tunneling rate is computed and the conditions needed to observe quantum collapse of a skyrmion in a magnetic film are discussed.