Volume 85, Number 5, March 2009
|Number of page(s)
|Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
|20 March 2009
Dynamical magnetoelectric effects induced by the Dzyaloshinskii-Moriya interaction in multiferroics
Institut für Physik, Martin-Luther Universität Halle-Wittenberg - Heinrich-Damerow-Str.4 06120 Halle (Saale), Germany, EU
Accepted: 13 February 2009
We study the dynamical interplay between ferroelectricity and magnetism in a multiferroic with a helical magnetic order. We show that the dynamical exchange-striction induces a biquadratic interaction between the spins and transverse phonons resulting in quantum fluctuations of the spontaneous ferroelectric polarization in the ferroelectric phase. The hybridization between the spin wave and the fluctuation of the electric polarization leads to low-lying transverse phonon modes. Those are perpendicular to and to the helical spins at small wave vector but then turn parallel to at a wave vector close to the magnetic modulation vector. For helical magnetic structure, the spin chirality which determines the direction of , also possesses a long-range order. Due to the dynamical Dzyaloshiskii-Moriya interaction, the spin chirality is strongly coupled to the spin fluctuation which implies an on-site inversion of the spin chirality in the ordered spin-(1/2) system and results in a finite scattering intensity of polarized neutrons from a cycloidal helimagnet.
PACS: 75.80.+q – Magnetomechanical and magnetoelectric effects, magnetostriction / 71.70.Ej – Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect / 77.80.-e – Ferroelectricity and antiferroelectricity
© EPLA, 2009
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.