One-way transparency of four-coloured spin-wave excitations in multiferroic materials

The coupling between spins and electric dipoles governs magnetoelectric phenomena in multiferroics. The dynamical magnetoelectric effect, which is an inherent attribute of the spin excitations in multiferroics, drastically changes the optical properties of these compounds compared with conventional...

Full description

Saved in:
Bibliographic Details
Published in:Nature communications 2014-02, Vol.5 (1), p.3203-3203, Article 3203
Main Authors: Kézsmárki, I., Szaller, D., Bordács, S., Kocsis, V., Tokunaga, Y., Taguchi, Y., Murakawa, H., Tokura, Y., Engelkamp, H., Rõõm, T., Nagel, U.
Format: Article
Language:English
Subjects:
49
49/90
49/91
639/301/119/996
639/301/119/997
64
82
Humanities and Social Sciences
multidisciplinary
Science
Science (multidisciplinary)
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The coupling between spins and electric dipoles governs magnetoelectric phenomena in multiferroics. The dynamical magnetoelectric effect, which is an inherent attribute of the spin excitations in multiferroics, drastically changes the optical properties of these compounds compared with conventional materials where light-matter interaction is expressed only by the dielectric permittivity or magnetic permeability. Here we show via polarized terahertz spectroscopy studies on multiferroic Ca 2 CoSi 2 O 7 , Sr 2 CoSi 2 O 7 and Ba 2 CoGe 2 O 7 that such magnetoeletric spin excitations exhibit quadrochroism, that is, they have different colours for all the four combinations of the two propagation directions (forward or backward) and the two orthogonal polarizations of a light beam. We demonstrate that one-way transparency can be realized for spin-wave excitations with sufficiently strong optical magnetoelectric effect. Furthermore, the transparent and absorbing directions of light propagation can be reversed by external magnetic fields. This magnetically controlled optical-diode function of magnetoelectric multiferroics may open a new horizon in photonics. Multiferroics can exhibit directional dichroism, which means that they can exhibit different absorption for light travelling forward and backward. Here, the authors show that in multiferroics with a strong optical magnetoelectric effect magnetically controlled one-way transparency can be realized.
ISSN:2041-1723
2041-1723
DOI:10.1038/ncomms4203