Thielemann-Kühn, N.; Amrhein, T.; Bronsch, W.; Jana, S.; Pontius, N.; Engel, R.Y.; Miedema, P.S.; Legut, D.; Carva, K.; Atxitia, U.; van Kuiken, B.E.; Teichmann, M.; Carley, R.E.; Mercadier, L.; Yaroslavtsev, A.; Mercurio, G.; Le Guyader, L.; Agarwal, N.; Gort, R.; Scherz, A.; Dziarzhytski, S.; Brenner, G.; Pressacco, F.; Wang, R.P.; Schunck, J.O.; Sinha, M.; Beye, M.; Chiuzbaian, G.S.; Oppeneer, P.M.; Weinelt, M.; Schüßler-Langeheine, C.: Optical control of 4f orbital state in rare-earth metals. Science Advances 10 (2024), p. eadk9522/1-10
10.1126/sciadv.adk9522
Open Access Version
Abstract:
A change of orbital state alters the coupling between ions and their surroundings drastically. Orbital excitations are hence key to understand and control interaction of ions. Rare-earth elements with strong magneto-crystalline anisotropy (MCA) are important ingredients for magnetic devices. Thus, control of their localized 4f magnetic moments and anisotropy is one major challenge in ultrafast spin physics. With time-resolved x-ray absorption and resonant inelastic scattering experiments, we show for Tb metal that 4f-electronic excitations out of the ground-state multiplet occur after optical pumping. These excitations are driven by inelastic 5d-4f-electron scattering, altering the 4f-orbital state and consequently the MCA with important implications for magnetization dynamics in 4f-metals and more general for the excitation of localized electronic states in correlated materials.