2008/03/06 by A. B. Harris, M. Kenzelmann, Amnon Aharony +2
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Ferroelectric and Piezoelectric Materials #Multiferroics and related materials #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.78.014407
16 pages, 4 figures
arxiv created 2008/03/06 · openalex publication_date 2008/07/03 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Starting from the irreducible representations of the group of the wave vector, we construct the spin-wave functions consistent with inversion symmetry, neglected in the usual representation analysis. We obtain the relation between the basis functions of different members of the star of the wave vector. We introduce order parameters and determine their transformation properties under the operations of the space group of the paramagnetic crystal. The results are applied to construct terms in the magnetoelectric interaction, which are quadratic and quartic in the magnetic order parameters. The higher-order magnetoelectric interactions can in principle induce components of the spontaneous polarization, which are not allowed by the lowest-order magnetoelectric interaction. We also obtain the relation between the spin-wave functions of the incommensurate phase and those of the commensurate phase, which lead to analogous relations between the order parameters of these two phases.