Itinerant and Localized Magnetization Dynamics in Antiferromagnetic Ho

• Published in: Physical review letters Vol. 116; no. 25; p. 257202
• Main Authors: Rettig, L, Dornes, C, Thielemann-Kühn, N, Pontius, N, Zabel, H, Schlagel, D L, Lograsso, T A, Chollet, M, Robert, A, Sikorski, M, Song, S, Glownia, J M, Schüßler-Langeheine, C, Johnson, S L, Staub, U
• Format: Journal Article
• Language: English
• Published: United States American Physical Society (APS) 24-06-2016
• Subjects: Antiferromagnetism; Demagnetization; Dynamics; Electronics; Femtosecond; Ferromagnetism; MATERIALS SCIENCE; Satellites; X-rays
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.116.257202

Using femtosecond time-resolved resonant magnetic x-ray diffraction at the Ho L_{3} absorption edge, we investigate the demagnetization dynamics in antiferromagnetically ordered metallic Ho after femtosecond optical excitation. Tuning the x-ray energy to the electric dipole (E1, 2p→5d) or quadrupole (E2, 2p→4f) transition allows us to selectively and independently study the spin dynamics of the itinerant 5d and localized 4f electronic subsystems via the suppression of the magnetic (2 1 3-τ) satellite peak. We find demagnetization time scales very similar to ferromagnetic 4f systems, suggesting that the loss of magnetic order occurs via a similar spin-flip process in both cases. The simultaneous demagnetization of both subsystems demonstrates strong intra-atomic 4f-5d exchange coupling. In addition, an ultrafast lattice contraction due to the release of magneto-striction leads to a transient shift of the magnetic satellite peak.