New paper: Lattice dynamics and ultrafast energy flow between electrons, spins, and phonons in a 3d ferromagnet
The response of magnetic materials to femtosecond laser excitation is governed by the interplay of electronic, magnetic, and lattice degrees of freedom. While many experiments investigated the electronic or the spin response, here we studied the lattice response of ferromagnetic nickel using femtosecond electron diffraction. To interpret our results for the lattice heating, we compared them to DFT calculations in combination with models for the microscopic energy flow between the different subsystems. The comparison revealed that the energy cost of demagnetization has a strong impact on the lattice dynamics. We achieved a consistent description of the electron, spin, and lattice dynamics by employing energy-conserving atomistic spin dynamics simulations. Our results provide a clear picture of the ultrafast energy flow between electronic, magnetic, and lattice degrees of freedom.