title: Long-living terahertz magnons in ultrathin metallic ferromagnets.
abstract: The main idea behind magnonics is to use the elementary magnetic excitations (magnons) for information transfer and processing. One of the main challenges, hindering the application of ultrafast terahertz magnons in magnonics, has been the short lifetime of these excitations in metallic ferromagnets. Here, we demonstrate that the engineering of the electronic structure of a ferromagnetic metal, by reducing its dimensionality and changing its chemical composition, opens a possibility to strongly suppress the relaxation channels of terahertz magnons and thereby enhance the magnons' lifetime. For the first time, we report on the long-lived terahertz magnons excited in ultrathin metallic alloy films. On the basis of the first-principles calculations, we explain the microscopic nature of the long lifetime being a consequence of the peculiar electronic hybridizations of the species. We further demonstrate a way of tailoring magnon energies (frequencies) by varying the chemical composition of the film.
authors.affiliation: Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany.
authors.forename: H J
authors.initials: HJ
authors.lastname: Qin
authors.affiliation: Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany.
authors.forename: Kh
authors.initials: Kh
authors.lastname: Zakeri
authors.affiliation: 1] Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany [2] Wilhelm Ostwald Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstrasse 2, 04103 Leipzig, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Ernst
authors.affiliation: Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany.
authors.forename: L M
authors.initials: LM
authors.lastname: Sandratskii
authors.affiliation: 1] Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany [2] Informatik Consulting Systems AG, Sonnenbergstr. 13, 70184 Stuttgart, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Buczek
authors.affiliation: Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Marmodoro
authors.affiliation: Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany.
authors.forename: T-H
authors.initials: TH
authors.lastname: Chuang
authors.affiliation: 1] Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany [2] Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: 1] Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany [2] Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, 06120 Halle, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Kirschner