Quantum dynamics of vortices in mesoscopic magnetic disks

TL;DR

This paper develops a quantum model for vortex depinning in mesoscopic magnetic disks, calculating instanton solutions, crossover temperature, and depinning rates, and fits the theory to experimental data.

Contribution

It introduces a quantum depinning model for magnetic vortices in disk geometries using Caldeira-Leggett theory, including explicit solutions and parameter fitting.

Findings

Computed instanton solutions for various magnetic fields.

Derived expressions for crossover temperature and depinning rate.

Fitted theoretical model to experimental data.

Abstract

Model of quantum depinning of magnetic vortex cores from line defects in a disk geometry and under the application of an in-plane magnetic field has been developed within the framework of the Caldeira-Leggett theory. The corresponding instanton solutions are computed for several values of the magnetic field. Expressions for the crossover temperature Tc and for the depinning rate \Gamma(T) are obtained. Fitting of the theory parameters to experimental data is also presented.