Electrical detection of spin pumping due to the precessing magnetization of a single ferromagnet

TL;DR

This paper demonstrates direct electrical detection of spin pumping from a single ferromagnet into adjacent normal metals, revealing how material properties influence the generated voltage during ferromagnetic resonance.

Contribution

It provides experimental evidence of spin pumping detection via electrical signals in a simple device structure, confirming theoretical predictions about material dependence.

Findings

Spin pumping causes measurable d.c. voltage in normal metals.

Material properties of the normal metal affect the voltage magnitude.

The experimental results agree with theoretical models of spin-dependent conductivities.

Abstract

We report direct electrical detection of spin pumping, using a lateral normal metal/ferromagnet/normal metal device, where a single ferromagnet in ferromagnetic resonance pumps spin polarized electrons into the normal metal, resulting in spin accumulation. The resulting backflow of spin current into the ferromagnet generates a d.c. voltage due to the spin dependent conductivities of the ferromagnet. By comparing different contact materials (Al and /or Pt), we find, in agreement with theory, that the spin related properties of the normal metal dictate the magnitude of the d.c. voltage.