Optical control of 4 f orbital state in rare-earth metals
Nele Thielemann-Kühn, Tim Amrhein, Wibke Bronsch, Somnath Jana, Niko Pontius, Robin Y. Engel, Piter S. Miedema, Dominik Legut, Karel Carva, Unai Atxitia, Benjamin E. van Kuiken, Martin Teichmann, Robert E. Carley, Laurent Mercadier, Alexander Yaroslavtsev, Giuseppe Mercurio, Loïc Le Guyader, Naman Agarwal, Rafael Gort, Andres Scherz, Siarhei Dziarzhytski, Günter Brenner, Federico Pressacco, Ru-Pan Wang, Jan O. Schunck, Mangalika Sinha, Martin Beye, Gheorghe S. Chiuzbăian, Peter M. Oppeneer, Martin Weinelt, Christian Schüßler-Langeheine- Multidisciplinary
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 4 f 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 4 f -electronic excitations out of the ground-state multiplet occur after optical pumping. These excitations are driven by inelastic 5 d -4 f -electron scattering, altering the 4 f -orbital state and consequently the MCA with important implications for magnetization dynamics in 4 f -metals and more general for the excitation of localized electronic states in correlated materials.