title: Ultrafast Magnetism of a Ferrimagnet across the Spin-Flop Transition in High Magnetic Fields.
abstract: We show that applying magnetic fields up to 30 T has a dramatic effect on the ultrafast spin dynamics in ferrimagnetic GdFeCo. Upon increasing the field beyond a critical value, the dynamics induced by a femtosecond laser excitation strongly increases in amplitude and slows down significantly. Such a change in spin response is explained by different dynamics of the Gd and FeCo magnetic sublattices following a spin-flop phase transition from a collinear to a noncollinear spin state.
authors.affiliation: Radboud University, Institute for Molecules and Materials, Nijmegen 6525 AJ, The Netherlands.|High Field Magnet Laboratory (HFML-EMFL), Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Becker
authors.affiliation: College of Science and Technology, Nihon University, 24-1 Narashinodai 7-chome, Funabashi-shi, Chiba 274-8501, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Tsukamoto
authors.affiliation: Radboud University, Institute for Molecules and Materials, Nijmegen 6525 AJ, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Kirilyuk
authors.affiliation: High Field Magnet Laboratory (HFML-EMFL), Radboud University, Toernooiveld 7, 6525 ED NIJMEGEN, The Netherlands.
authors.forename: J C
authors.initials: JC
authors.lastname: Maan
authors.affiliation: Radboud University, Institute for Molecules and Materials, Nijmegen 6525 AJ, The Netherlands.
authors.forename: Th
authors.initials: T
authors.lastname: Rasing
authors.affiliation: High Field Magnet Laboratory (HFML-EMFL), Radboud University, Toernooiveld 7, 6525 ED NIJMEGEN, The Netherlands.
authors.forename: P C M
authors.initials: PC
authors.lastname: Christianen
authors.affiliation: Radboud University, Institute for Molecules and Materials, Nijmegen 6525 AJ, The Netherlands.
authors.forename: A V
authors.initials: AV
authors.lastname: Kimel