Eur. Phys. J. B (2013) 86: 376
https://doi.org/10.1140/epjb/e2013-40085-4

Regular Article

Dynamical magnetoelectric effects in the distorted spiral multiferroic magnets

Zhejiang Institute of Modern Physics and Department of Physics, Zhejiang University, Hangzhou 310027, P.R. China

^a e-mail: hbchen@zju.edu.cn

Received: 1 February 2013
Received in final form: 13 May 2013
Published online: 9 September 2013

Abstract

We investigate the dynamical interplay between magnetic and ferroelectric orders in a multiferroics with distorted spiral order. We find that the combing effect of the distortion of the spiral order and the effective spin anisotropy induced by the spin-lattice coupling results in the lifting of the degenerate gapped mode at the ordering wave vector, which is qualitatively in agreement with the experimental observations. In analogy to the perfect spiral spin structure, the electromagnon can be assigned to spin wave mode of the distorted helimagnet at the ordering wave vector. The electromagnon in the distorted helimagnets is also affected by the helix distortion which can be experimentally controlled.