Current-driven resonant excitation of magnetic vortex

TL;DR

This paper demonstrates that a magnetic vortex core in a nanodot can be resonantly excited by an AC spin-polarized current, with the resonance frequency tunable by the dot shape, confirmed through micromagnetic simulations and resistance measurements.

Contribution

It introduces a method to resonantly excite magnetic vortex cores using AC spin currents and shows how the resonance frequency can be tuned by the dot shape.

Findings

Resonant excitation of vortex core achieved via AC spin-polarized current.

Resonance frequency can be tuned by altering the nanodot shape.

Experimental resistance measurements confirm simulation results.

Abstract

A magnetic vortex core in a ferromagnetic circular nanodot has a resonance frequency originating from the confinement of the vortex core. By the micromagnetic simulation including the spin-transfer torque, we show that the vortex core can be resonantly excited by an AC (spin-polarized) current through the dot and that the resonance frequency can be tuned by the dot shape. The resistance measurement under the AC current successfully detects the resonance at the frequency consistent with the simulation.