Electromagnon excitations in multiferroics

DIPC Seminars

Speaker
Rogério de Sousa, Department of Physics and Astronomy, University of Victoria, B.C., Canada
When
2011/05/05
14:00
Place
Donostia International Physics Center (DIPC).Paseo Manuel de Lardizabal, 4 (nearby the Facultad de Quimica), Donostia
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Electromagnon excitations in multiferroics The coexistence of ferroelectricity and magnetism in multiferroic materials gives rise to cross-correlation between electric and magnetic degrees of freedom. A notable consequence is that the elementary excitations are not purely magnetic or ferroelectric in character: The spin waves are admixed with vibrational modes of the electric polarization, giving rise to electric dipole active magnons, the so-called electromagnons. Electromagnons are particularly interesting in the room temperature multiferroic BiFeO3, that exhibits a large ferroelectric moment coexisting with a spiral magnetic phase in the form of a cycloid. A recent experiment demonstrated gigantic electric-field tuning of these excitations, three orders of magnitude larger than previous measurements in other materials. The origin of this amazing electric-field control lies in the sensitivity of the cycloid magnet to an external electric field. Contact person at DIPC: Ivo Souza (ivo_souza@ehu.es) Would you want to schedule to meet with the speaker, please contact Dr. Souza who will put together the schedule of the visit.