Josephson junction with a magnetic vortex

TL;DR

This paper investigates how a magnetic vortex in a ferromagnetic disk influences Josephson tunneling, proposing a new method to measure nanoscale vortex motion via Josephson current variations.

Contribution

It analytically and numerically demonstrates the effect of vortex core displacement on Josephson current, linking magnetic vortex dynamics with superconducting tunneling phenomena.

Findings

Josephson current is sensitive to vortex core displacement.

Analytical and numerical models show measurable current changes.

Potential application in nanoscale magnetic vortex motion detection.

Abstract

We have studied Josephson tunneling through a circularly polarized micron or submicron-size disk of a soft ferromagnetic material. Such a disk contains a vortex that exhibits rich classical dynamics and has recently been proposed as a tool to study quantum dynamics of the nanoscale vortex core. The change in the Josephson current that is related to a tiny displacement of the vortex core has been computed analytically and plotted numerically for permalloy disks used in experiments. It is shown that a Josephson junction with a magnetic disk in the vortex state can be an interesting physical system that may be used to measure the nanoscale motion of the magnetic vortex.