Transverse and Unidirectional Spin Pumping

TL;DR

This paper predicts a novel form of spin pumping driven by electromagnetic radiation, generating transverse and unidirectional spin currents parallel to the interface, which could advance spintronic device control.

Contribution

It introduces the concept of Hall-type and unidirectional spin pumping driven by electromagnetic fields, expanding the mechanisms for spin current generation beyond conventional methods.

Findings

Predicts transverse spin currents driven by electromagnetic radiation.

Shows the spin current is unidirectional and controllable by magnetization.

Highlights the efficiency of electric field coupling in spin pumping.

Abstract

Conventional spin pumping, driven by magnetization dynamics, is longitudinal since the pumped spin current flows normal to the interface between the ferromagnet and the conductor. We predict \textit{Hall-type/transverse} and \textit{unidirectional} spin pumping into conductors by near-field electromagnetic radiation emitted by, \textit{e.g.}, magnetization dynamics. The joint effect of the electric and magnetic fields results in a pure spin current flowing parallel to the interface, i.e., a Hall-type spin pumping, which is highly efficient due to the strong coupling to the electric field. Such a transverse spin current is unidirectional, with the spatial distribution controlled by the magnetization direction. Our finding reveals a robust approach for generating and manipulating spin currents in future low-dimensional spintronic and orbitronic devices.