Optical control of 4f orbital state in rare-earth metals

• Main Authors: 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, Guyader, L. Le, Agarwal, N, Gort, R, Scherz, A, Dziarzhytski, S, Brenner, G, Pressacco, F, Wang, R, Schunck, J. O, Sinha, M, Beye, M, Chiuzbăian, G. S, Oppeneer, P. M, Weinelt, M, Schüßler-Langeheine, C
• Format: Journal Article
• Language: English
• Published: 18-06-2021
• Subjects: Physics - Materials Science
• DOI: 10.48550/arxiv.2106.09999

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 (RE) 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, alter 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.