Spin-transfer-driven ferromagnetic resonance of individual nanomagnets

TL;DR

This paper introduces a novel technique for measuring ferromagnetic resonance in individual nanoscale ferromagnets, revealing detailed insights into their magnetic dynamics and spin-transfer effects.

Contribution

The study presents a new method for FMR measurements on tiny nanomagnets, enabling analysis of their magnetic modes and response regimes with high precision.

Findings

Identification of simple FMR and phase locking regimes

Detailed characterization of resonance frequencies, amplitudes, and linewidths

Insights into exchange, damping, and spin-transfer torques in nanostructures

Abstract

We demonstrate a technique that enables ferromagnetic resonance (FMR) measurements of the normal modes for magnetic excitations in individual nanoscale ferromagnets, smaller in volume by a factor of 1000 than can be probed by other methods. The measured peak shapes indicate two regimes of response: simple FMR and phase locking. Studies of the resonance frequencies, amplitudes, and linewidths as a function of microwave power, DC current, and magnetic field provide detailed new information about the exchange, damping, and spin-transfer torques that govern the dynamics in magnetic nanostructures.