Goldstone modes and electromagnon fluctuations in the conical cycloid state of a multiferroic
Strongly Correlated Electrons
2008-11-07 v2 Materials Science
Abstract
Using a phenomenological Ginzburg-Landau theory for the magnetic conical cycloid state of a multiferroic, which has been recently reported in the cubic spinel CoCrO, we discuss its low-energy fluctuation spectrum. We identify the Goldstone modes of the conical cycloidal order, and deduce their dispersion relations whose signature anisotropy in momentum space reflects the symmetries broken by the ordered state. We discuss the soft polarization fluctuations, the `electromagnons', associated with these magnetic modes and make several experimental predictions which can be tested in neutron scattering and optical experiments.
Keywords
Cite
@article{arxiv.0710.4551,
title = {Goldstone modes and electromagnon fluctuations in the conical cycloid state of a multiferroic},
author = {Sumanta Tewari and Chuanwei Zhang and John Toner and S. Das Sarma},
journal= {arXiv preprint arXiv:0710.4551},
year = {2008}
}
Comments
5 pages, 2 eps figures, accepted by Physical Review B