  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.
