title: Enhanced directional dichroism of terahertz light in resonance with magnetic excitations of the multiferroic Ba2CoGe2O7 oxide compound.
abstract: We propose that concurrently magnetic and ferroelectric, i.e., multiferroic, compounds endowed with electrically active magnetic excitations (electromagnons) provide a key to producing large directional dichroism for long wavelengths of light. By exploiting the control of ferroelectric polarization and magnetization in a multiferroic oxide Ba(2)CoGe(2)O(7), we demonstrate the realization of such a directional light-switch function at terahertz frequencies in resonance with the electromagnon absorption. Our results imply that this hidden potential is present in a broad variety of multiferroics.
authors.affiliation: Multiferroics Project, ERATO, Japan Science and Technology Agency, Japan c/o The University of Tokyo, Tokyo 113-8656, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Kézsmárki
authors.forename: N
authors.initials: N
authors.lastname: Kida
authors.forename: H
authors.initials: H
authors.lastname: Murakawa
authors.forename: S
authors.initials: S
authors.lastname: Bordács
authors.forename: Y
authors.initials: Y
authors.lastname: Onose
authors.forename: Y
authors.initials: Y
authors.lastname: Tokura