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arXiv · 1010.5420

Giant directional dichroism of terahertz light in resonance with magnetic excitations of the multiferroic oxide BaCo$_2$Ge$_2$O$_7$

I. Kezsmarki·N. Kida·H. Murakawa·S. Bordacs·Y. Onose·Y. Tokura
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Abstract

We propose that concurrently magnetic and ferroelectric, i.e. multiferroic, compounds endowed with electrically-active magnetic excitations (electromagnons) provide a key to produce large directional dichroism for long wavelengths of light. By exploiting the control of ferroelectric polarization and magnetization in a multiferroic oxide Ba$_2$CoGe$_2$O$_7$, we demonstrate the realization of such a directional light-switch function at terahertz frequecies in resonance with the electromagnon absorption. Our results imply that this hidden potential is present in a broad variety of multiferroics.

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I. Kezsmarki, N. Kida, H. Murakawa, S. Bordacs, Y. Onose, Y. Tokura. 2010-10-26. Giant directional dichroism of terahertz light in resonance with magnetic excitations of the multiferroic oxide BaCo$_2$Ge$_2$O$_7$. https://doi.org/10.1103/physrevlett.106.057403

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