# Domain wall dynamics due to femtosecond laser-induced superdiffusive spin transport

## TL;DR

This paper models how femtosecond laser pulses induce superdiffusive spin transport, leading to rapid domain wall motion via spin-transfer torque, advancing understanding of ultrafast magnetic manipulation.

## Contribution

It introduces a superdiffusive spin-dependent transport model to explain laser-induced domain wall dynamics, highlighting the role of spin currents in ultrafast magnetic control.

## Key findings

- Laser pulses near domain walls generate strong spin currents.
- Spin transfer enhances ultrafast demagnetization.
- Domain walls can move several nanometers in hundreds of femtoseconds.

## Abstract

Manipulation of magnetic domain walls via a helicity-independent laser pulse has recently been experimentally demonstrated and various physical mechanisms leading to domain wall dynamics have been discussed. Spin-dependent superdiffusive transport of hot electrons has been identified as one of the possible ways how to affect a magnetic domain wall. Here, we develop a model based on superdiffusive spin-dependent transport to study the laser-induced transport of hot electrons through a smooth magnetic domain wall. We show that the spin transfer between neighboring domains can enhance ultrafast demagnetization in the domain wall. More importantly, our calculations reveal that when the laser pulse is properly focused on to the vicinity of the domain wall, it can excite sufficiently strong spin currents to generate a spin-transfer torque that can rapidly move the magnetic domain wall by several nanometers in several hundreds of femtoseconds, leading to a huge nonequilibrium domain wall velocity.