Frequency and power dependence of spin-current emission by spin pumping in a thin film YIG/Pt system

TL;DR

This study investigates how the frequency and power influence spin-current emission in a YIG/Pt thin film system, revealing nonlinear effects and enhanced emission at low frequencies through experimental measurements.

Contribution

It provides new insights into the frequency and power dependence of spin-current emission in YIG/Pt systems, highlighting nonlinear phenomena at low frequencies.

Findings

Enhanced spin current emission at low frequencies

Dependence of voltage signal on frequency and power

Observation of nonlinear effects in spin pumping

Abstract

This paper presents the frequency dependence of the spin current emission in a hybrid ferrimagnetic insulator/normal metal system. The system is based on a ferrimagnetic insulating thin film of Yttrium Iron Garnet (YIG, 200 nm) grown by liquid-phase-epitaxy (LPE) coupled with a normal metal with a strong spin-orbit coupling (Pt, 15 nm). The YIG layer presents an isotropic behaviour of the magnetization in the plane, a small linewidth, and a roughness lower than 0.4 nm. Here we discuss how the voltage signal from the spin current detector depends on the frequency [0.6 - 7 GHz], the microwave power, Pin, [1 - 70 mW], and the in-plane static magnetic field. A strong enhancement of the spin current emission is observed at low frequencies, showing the appearance of non-linear phenomena.