Current-induced spin-wave excitations in a single ferromagnetic layer

TL;DR

This paper reports the discovery of current-induced spin-wave excitations in a single ferromagnetic layer, revealing a new spin-torque transfer effect that occurs without multilayer structures and depends linearly on external magnetic fields.

Contribution

It introduces a novel spin-torque transfer effect in a single ferromagnetic layer, expanding understanding beyond multilayer-based systems.

Findings

Abrupt resistance changes at specific current densities due to spin wave excitations

Critical current depends linearly on external perpendicular magnetic field

Effect arises from current-driven heterogeneity in a uniform ferromagnetic layer

Abstract

A new current induced spin-torque transfer effect has been observed in a single ferromagnetic layer without resorting to multilayers. At a specific current density of one polarity injected from a point contact, abrupt resistance changes due to current-induced spin wave excitations have been observed. The critical current at the onset of spin-wave excitations depends linearly on the external field applied perpendicular to the layer. The observed effect is due to current-driven heterogeneity in an otherwise uniform ferromagnetic layer.