title: Laser-Driven Multiferroics and Ultrafast Spin Current Generation.
abstract: We propose an ultrafast way to generate spin chirality and spin current in a class of multiferroic magnets using a terahertz circularly polarized laser. Using the Floquet formalism for periodically driven systems, we show that it is possible to dynamically control the Dzyaloshinskii-Moriya interaction in materials with magnetoelectric coupling. This is supported by numerical calculations, by which additional resonant phenomena are found. Specifically, when a static magnetic field is applied in addition to the circularly polarized laser, a large resonant enhancement of spin chirality is observed resembling the electron spin resonance. Spin current is generated when the laser is spatially modulated by chiral plasmonic structures and could be detected using optospintronic devices.
authors.affiliation: Department of Physics, Ibaraki University, Mito, Ibaraki 310-8512, Japan.|Department of Physics and Mathematics, Aoyama-Gakuin University, Sagamihara, Kanagawa 229-8558, Japan.|Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan.|ERATO, Japan Science and Technology Agency, Sendai, Miyagi 980-8577, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sato
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, 24 quai Ernest-Ansermet, Geneva 1211, Switzerland.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Takayoshi
authors.affiliation: Max-Planck-Institut für Physik komplexer Systeme (MPI-PKS), Nöthnitzer Straße 38, Dresden 01187, Germany.|Max-Planck-Institut für Chemische Physik fester Stoffe (MPI-CPfS), Nöthnitzer Straße 40, Dresden 01187, Germany.
authors.forename: Takashi
authors.initials: T
authors.lastname: Oka