Abstract
Electromagnon excitations in multiferroic orthorhombic are shown to result from the Heisenberg coupling between spins despite the fact that the static polarization arises from the much weaker Dzyaloshinskii-Moriya exchange interaction. We present a model incorporating the structural characteristics of this family of manganites that is confirmed by far infrared transmission data as a function of temperature and magnetic field and inelastic neutron scattering results. A deep connection is found between the magnetoelectric dynamics of the spiral phase and the static magnetoelectric coupling in the collinear phase of this family of manganites.
- Received 19 November 2008
DOI:https://doi.org/10.1103/PhysRevLett.102.047203
©2009 American Physical Society