Attenuation characteristics of spin pumping signal due to travelling spin waves

TL;DR

This paper investigates how travelling spin waves affect the spin pumping signal in a Pt/NiFe bilayer, extending theoretical models and experimentally demonstrating the attenuation of the signal with increasing frequency.

Contribution

The study extends the theoretical framework of spin pumping to include contributions from travelling spin waves and derives equations for their effective area.

Findings

Travelling spin waves cause a more rapid decrease in spin pumping amplitude with frequency.

Experimental data aligns well with the extended theoretical model.

Travelling waves influence the efficiency of spin pumping signals.

Abstract

The authors have investigated the contribution of the surface spin waves to spin pumping. A Pt/NiFe bilayer has been used for measuring spin waves and spin pumping signals simultaneously. The theoretical framework of spin pumping resulting from ferromagnetic resonance has been extended to incorporate spin pumping due to spin waves. Equations for the effective area of spin pumping due to spin waves have been derived. The amplitude of the spin pumping signal resulting from travelling waves is shown to decrease more rapidly with precession frequency than that resulting from standing waves and show good agreement with the experimental data.