Magnetic noise induced by dc current in a micron-size magnetic wire

TL;DR

This study investigates magnetic noise spectra caused by dc current in micron-sized ferromagnetic wires, revealing resonance behaviors linked to magnetization precession and Joule heating effects.

Contribution

It provides a detailed analysis of magnetic noise spectra and their dependence on magnetic fields, supported by an analytical stochastic model.

Findings

Resonance frequency observed in noise spectra

Magnetic field dependence explained by the model

Noise attributed to resistance oscillation from magnetization precession

Abstract

The magnetic noise spectra induced by direct-current (dc) current flowing through a micron-scale ferromagnetic wire have been investigated. We have observed the noise spectra with a resonance frequency. Under the application of the magnetic field in the plane, the magnetic field dependences of the resonance frequency and amplitude were well interpreted by the analytical calculation based on the stochastic model. The noise spectra are attributable to the resistance oscillation reflecting the uniform magnetization precession which is produced by the Joule heating due to the dc current.