Ultrafast spin current generation in ferromagnetic thin films

TL;DR

This paper demonstrates that femtosecond laser pulses can generate oscillating spin currents in ferromagnetic thin films through ballistic electron dynamics, advancing understanding of ultrafast spintronic phenomena.

Contribution

It reveals that laser-induced spin currents originate from ballistic electrons oscillating within the film, a novel mechanism for ultrafast spin current generation.

Findings

Oscillating spin currents can be generated with femtosecond laser pulses.

The spin current intensity depends on the electric field strength.

Ballistic electrons are responsible for the spin current in the film.

Abstract

Spin currents have been shown to play a key role in the ultrafast laser-driven demagnetization process in ferromagnetic thin films. Here, we show that an oscillating spin current can be generated in the film via the application of a femtosecond laser pulse in the visible range. In particular, we prove that the spin current is due to ballistic electrons traveling back and forth in the film. The dependence of the current intensity on the driving electric field is also investigated.