Speaker
David Szaller
(Budapest University of Technology and Economics)
Description
In physical systems simultaneously breaking time-reversal and spatial inversion symmetries the strength of absorption for two counter-propagating light beams can be different irrespective of the polarization state of light [1], which phenomenon is termed as non-reciprocal directional dichroism. Until recent experiments on multiferroic materials [2, 3] this effect was generally found to be weak.
Directional dichroism of multiferroics in the far-infrared spectral range is the consequence of the optical magnetoelectric effect, i.e. the coupled dynamics of spins and local electric dipoles[4]. Spin-wave modes in multiferroics can simultaneously be excited by the electric and magnetic components of light, hence, they can be viewed as the “elementary excitations” of such hybrid magnetoelectric response. Indeed multiferroic Ni3TeO6 [5] shows strong directional dichroism in its spin excitations, even for unpolarized light. The temperature- and magnetic field dependence of these resonances was followed up to the Néel temperature and up to 30 T, respectively.
Primary author
David Szaller
(Budapest University of Technology and Economics)
Co-authors
Dr
Hans Engelkamp
(High Field Magnet Laboratory, Radboud University Nijmegen 1 Toernooiveld, Nijmegen, The Netherlands, 6525 ED)
Prof.
István Kézsmárki
(Department of Physics, Budapest University of Technology and Economics, 8 Budafoki út, Budapest, Hungary, H-1111; Department of Experimental Physics V., University of Augsburg 2 Universitätsstr., Augsburg, Germany, D-86135)
Dr
Jun Jie Yang
(Laboratory for Pohang Emergent Materials, Pohang University of Science and Technology Pohang 790-784, Korea)
Prof.
Sang Wook Cheong
(Laboratory for Pohang Emergent Materials, Pohang University of Science and Technology Pohang 790-784, Korea; Department of Physics and Astronomy, Rutgers University Piscataway, New Jersey 08854, USA; Rutgers Center for Emergent Materials, Rutgers University Piscataway, New Jersey 08854, USA)
Dr
Sergey Artyukhin
(Department of Physics and Astronomy, Rutgers University Piscataway, New Jersey 08854, USA)
