Electromagnons in multiferroic manganites

摘要: We review terahertz experiments on magnetoelectric excitations in rare earth multiferroic manganites RMnO3 with R = Gd, Tb, Dy, (Eu:Y). In all these compounds characteristic of the novel type, called electromagnons, have been observed for frequencies 10 cm−1<ν<30 cm−1. From spectroscopic point view electromagnons are responsible effects and, contrary to magnons, excited only by electric components electromagnetic wave. compositions appear as a broad Debye-like contribution sinusoidally modulated antiferromagnetic phase and transform well-defined magnetic structure becomes spiral. At lowest temperatures fine is observed, reflecting increasing complexity structure.