# Unconventional spin currents in magnetic films

## TL;DR

This paper reveals that in obliquely magnetized magnetic films, spin waves can generate transverse spin currents along the film normal without energy transfer, challenging traditional assumptions about spin wave propagation.

## Contribution

It demonstrates, through experimental and theoretical analysis, that spin waves in obliquely magnetized films produce transverse spin currents without energy transport, a novel phenomenon.

## Key findings

- Transverse spin currents occur in obliquely magnetized films.
- Spin waves can transfer angular momentum transversely without energy transfer.
- Experimental evidence supports the theoretical model.

## Abstract

A spin current - a flow of spin angular momentum - can be carried either by spin polarised free electrons or by magnons, the quanta of a moving collective oscillation of localised electron spins - a spin wave. Traditionally, it was assumed, that a spin wave in a magnetic film with spin-sink-free surfaces can transfer energy and angular momentum only along its propagation direction. In this work, using Brillouin light scattering spectroscopy in combination with a theory of dipole-exchange spin-wave spectra, we show that in obliquely magnetized free magnetic films the in-plane propagation of spin waves is accompanied by a transverse spin current along the film normal without any corresponding transverse transport of energy.