Abstract

The interaction between solid-state materials and laser pulses entails a ple-
thora of phenomena across a wide range of energy-scales and timescales. For
instance, high-energy laser pulses can be used for precise ablation [1], whereas
low-energy pulses can excite electrons, phonons and magnons [2] in a controlled
way. The development of femtosecond laser technologies has paved the way for
finer control of laser-matter interactions.
Exciting a metallic ferromagnet with a femtosecond laser pulse results in
ultrafast magnetization dynamics. This phenomenon, which occurs on sub-
picosecond timescales, underlies ultrafast spintronics. In this talk, I will present
theoretical and experimental studies addressing the key causes and effects of
the interplay between laser pulse, spin, charge, and heat transport at ultrafast
timescales [3]. Additionally, I will also describe the generation of spin and charge
currents due to magnetization dynamics and the role of the magnetoelectric
effect. I will also discuss how the simulation of complex Kerr responses at
sub-picosecond timescales is used to study laser-matter interactions [4].

[1] Baerbel Rethfeld et al. “Modelling ultrafast laser ablation”. In: Journal of
Physics D: Applied Physics 50.19 (2017), p. 193001.
[2] Anulekha De et al. “Dynamic interfacial effects in ultrathin ferromagnetic
bilayers”. In: arXiv preprint arXiv:2505.08490 (2025).
[3] Sanjay Ashok et al. “Influence of diffusive transport on ultrafast magneti-
zation dynamics”. In: Applied Physics Letters 120.14 (2022).
[4] Sanjay Ashok et al. “Signatures of ballistic and diffusive transport in the
time-dependent Kerr-response of magnetic materials”. In: New Journal of
Physics 27.6 (2025), p. 063001.