title: Itinerant and Localized Magnetization Dynamics in Antiferromagnetic Ho.
abstract: 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.
authors.affiliation: Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.|Current Address: Abteilung Physikalische Chemie, Fritz-Haber-Institut der MPG, Faradayweg 4-6, D-14195 Berlin, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Rettig
authors.affiliation: Institute for Quantum Electronics, Physics Department, ETH Zürich, 8093 Zürich, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Dornes
authors.affiliation: Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße 15, 12489 Berlin, Germany.|Institut für Physik und Astronomie, Universität Potsdam, Karl-Liebknecht-Straße 24/25, 14476 Potsdam-Golm, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Thielemann-Kühn
authors.affiliation: Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße 15, 12489 Berlin, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Pontius
authors.affiliation: Institute for Experimental Physics, Ruhr-Universität Bochum, 44780 Bochum, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Zabel
authors.affiliation: Division of Materials Sciences and Engineering, Ames Laboratory, Ames, Iowa 50011, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Schlagel
authors.affiliation: Department of Materials Science and Engineering, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: T A
authors.initials: TA
authors.lastname: Lograsso
authors.affiliation: Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: M
authors.initials: M
authors.lastname: Chollet
authors.affiliation: Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: A
authors.initials: A
authors.lastname: Robert
authors.affiliation: Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: M
authors.initials: M
authors.lastname: Sikorski
authors.affiliation: Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: S
authors.initials: S
authors.lastname: Song
authors.affiliation: Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Glownia
authors.affiliation: Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße 15, 12489 Berlin, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Schüßler-Langeheine
authors.affiliation: Institute for Quantum Electronics, Physics Department, ETH Zürich, 8093 Zürich, Switzerland.
authors.forename: S L
authors.initials: SL
authors.lastname: Johnson
authors.affiliation: Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.
authors.forename: U
authors.initials: U
authors.lastname: Staub