We propose that concurrently magnetic and ferroelectric, i.e., multiferroic, compounds endowed with electrically active magnetic excitations (electromagnons) provide a key to producing large directional dichroism for long wavelengths of light. By exploiting the control of ferroelectric polarization and magnetization in a multiferroic oxide Ba2CoGe2O 7, we demonstrate the realization of such a directional light-switch function at terahertz frequencies in resonance with the electromagnon absorption. Our results imply that this hidden potential is present in a broad variety of multiferroics.
ASJC Scopus subject areas
- Physics and Astronomy(all)