We have investigated ultrafast quenching of the Tb4f magnetic order in Co74Tb26 alloys, induced by femtosecond hot-electrons pulses. The hot-electron pulses were produced in specific non-magnetic capping layers by infrared fs laser pulses. Our experimental results show that sub-picosecond dynamics of Tb4f magnetic moments can be induced by non-thermal and thermal hot-electrons. We further demonstrate that the demagnetization efficiencies of non-thermal and thermal hot electrons are similar. However, the characteristic demagnetization times show values of 0.35 ps for non-thermal hot-electrons excitations and 1.2 ps for thermal hot-electrons excitations. We explain this temporal elongation by the propagation time of thermal hot-electrons through the 15 nm thick CoTb film.
@article{arxiv.1708.08919,
title = {Ultrafast hot-electron induced quenching of Tb4f magnetic order},
author = {T. Ferte and N. Bergeard and G. Malinowski and R. Abrudan and T. Kachel and K. Holldack and M. Hehn and C. Boeglin},
journal= {arXiv preprint arXiv:1708.08919},
year = {2017}
}