title: Spin-current emission governed by nonlinear spin dynamics.
abstract: Coupling between conduction electrons and localized magnetization is responsible for a variety of phenomena in spintronic devices. This coupling enables to generate spin currents from dynamical magnetization. Due to the nonlinearity of magnetization dynamics, the spin-current emission through the dynamical spin-exchange coupling offers a route for nonlinear generation of spin currents. Here, we demonstrate spin-current emission governed by nonlinear magnetization dynamics in a metal/magnetic insulator bilayer. The spin-current emission from the magnetic insulator is probed by the inverse spin Hall effect, which demonstrates nontrivial temperature and excitation power dependences of the voltage generation. The experimental results reveal that nonlinear magnetization dynamics and enhanced spin-current emission due to magnon scatterings are triggered by decreasing temperature. This result illustrates the crucial role of the nonlinear magnon interactions in the spin-current emission driven by dynamical magnetization, or nonequilibrium magnons, from magnetic insulators.
authors.affiliation: Department of Applied Physics and Physico-Informatics, Keio University, Yokohama 223-8522, Japan.
authors.forename: Takaharu
authors.initials: T
authors.lastname: Tashiro
authors.affiliation: Department of Applied Physics and Physico-Informatics, Keio University, Yokohama 223-8522, Japan.
authors.forename: Saki
authors.initials: S
authors.lastname: Matsuura
authors.affiliation: Department of Applied Physics and Physico-Informatics, Keio University, Yokohama 223-8522, Japan.
authors.forename: Akiyo
authors.initials: A
authors.lastname: Nomura
authors.affiliation: Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
authors.forename: Shun
authors.initials: S
authors.lastname: Watanabe
authors.affiliation: Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
authors.forename: Keehoon
authors.initials: K
authors.lastname: Kang
authors.affiliation: Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
authors.forename: Henning
authors.initials: H
authors.lastname: Sirringhaus
authors.affiliation: Department of Applied Physics and Physico-Informatics, Keio University, Yokohama 223-8522, Japan.|PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Ando