title: Evidence for electroactive excitation of the spin cycloid in TbMnO3.
abstract: Terahertz electromagnetic excitations in the multiferroic TbMnO3 single crystals are investigated across the magnetic field induced rotation of the magnetic spin cycloid. In addition to the electromagnon along the a axis, the detailed polarization analysis of the experimental spectra suggests the existence of an electroactive excitation for ac electric fields of the electromagnetic wave along the crystallographic c axis. This excitation is possibly the electroactive eigenmode of the spin-cycloid in TbMnO3, which has been predicted within the inverse Dzyaloshinskii-Moriya mechanism of magnetoelectric coupling.
authors.affiliation: Experimentelle Physik 4, Universität Würzburg, D-97074 Würzburg, Germany.
authors.forename: A M
authors.initials: AM
authors.lastname: Shuvaev
authors.forename: V D
authors.initials: VD
authors.lastname: Travkin
authors.forename: V Yu
authors.initials: VY
authors.lastname: Ivanov
authors.forename: A A
authors.initials: AA
authors.lastname: Mukhin
authors.forename: A
authors.initials: A
authors.lastname: Pimenov