Electrically driven spin excitation in a ferroelectric magnet DyMnO_3

Abstract

Temperature (5--250 K) and magnetic field (0--70 kOe) variations of the low-energy (1--10 meV) electrodynamics of spin excitations have been investigated for a complete set of light-polarization configurations for a ferroelectric magnet DyMnO${}_3$ by using terahertz time-domain spectroscopy. We identify the pronounced absorption continuum (1--8 meV) with a peak feature around 2 meV, which is electric-dipole active only for the light $E$-vector along the a-axis. This absorption band grows in intensity with lowering temperature from the spin-collinear paraelectric phase above the ferroelectric transition, but is independent of the orientation of spiral spin plane ($bc$ or $ab$), as shown on the original $P_{\mathrm{s}}$ (ferroelectric polarization) $\parallel c$ phase as well as the magnetic field induced $P_{\mathrm{s}}\parallel a$ phase. The possible origin of this electric-dipole active band is argued in terms of the large fluctuations of spins and spin-current.

New version, 11 pages including colored 8 figures

References in corpus (5)

• Spin current and magneto-electric effect in non-collinear magnets
• Role of the Dzyaloshinskii-Moriya interaction in multiferroic perovskites
• Colossal magnon-phonon coupling in multiferroic Eu${}_{0.75}$Y${}_{0.25}$MnO${}_3$
• Terahertz spectroscopy of electromagnons in Eu_{1-x}Y_xMnO_3
• Absence of commensurate ordering at the polarization flop transition in multiferroic DyMnO3

Cited by in corpus (7)

• Origin of electromagnon excitations in \textit{R}MnO${}_3$
• Terahertz time-domain spectroscopy of electromagnons in multiferroic perovskite manganites
• Magnetic and magnetoelectric excitations in TbMnO${}_3$
• Model for twin electromagnons and magnetically induced oscillatory polarization in multiferroic RMnO${}_3$
• Quantum Fluctuations of Chirality in One-Dimensional Spin-1/2 Multiferroics: Gapless Dielectric Response from Phasons and Chiral Solitons
• Electro-spinon in one-dimensional Mott insulator
• Electric-dipole active two-magnon excitation in {\textit{ab}} spiral spin phase of a ferroelectric magnet Gd${}_{\text{0.7}}$Tb${}_{\text{0.3}}$MnO${}_{\text{3}}$