Terahertz spectroscopy on Faraday and Kerr rotations in a quantum anomalous Hall state
| Autor: | Atsushi Tsukazaki, Yoshinori Tokura, Ken N. Okada, Masataka Mogi, Naoki Ogawa, Kei S. Takahashi, Youtarou Takahashi, Masashi Kawasaki, Ryutaro Yoshimi |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Terahertz radiation
Science Magnetoelectric effect General Physics and Astronomy Physics::Optics 02 engineering and technology 01 natural sciences Article General Biochemistry Genetics and Molecular Biology law.invention Condensed Matter::Materials Science law Quantum mechanics 0103 physical sciences 010306 general physics Faraday cage Quantum Physics Multidisciplinary Condensed matter physics Condensed Matter::Other Fine-structure constant General Chemistry 021001 nanoscience & nanotechnology Magnetic susceptibility Terahertz spectroscopy and technology Topological insulator 0210 nano-technology |
| Zdroj: | Nature Communications, Vol 7, Iss 1, Pp 1-6 (2016) Nature Communications |
| ISSN: | 2041-1723 |
| Popis: | Electrodynamic responses from three-dimensional topological insulators are characterized by the universal magnetoelectric term constituent of the Lagrangian formalism. The quantized magnetoelectric coupling, which is generally referred to as topological magnetoelectric effect, has been predicted to induce exotic phenomena including the universal low-energy magneto-optical effects. Here we report the experimental indication of the topological magnetoelectric effect, which is exemplified by magneto-optical Faraday and Kerr rotations in the quantum anomalous Hall states of magnetic topological insulator surfaces by terahertz magneto-optics. The universal relation composed of the observed Faraday and Kerr rotation angles but not of any material parameters (for example, dielectric constant and magnetic susceptibility) well exhibits the trajectory towards the fine structure constant in the quantized limit. Quantized magnetoelectric coupling, which induces exotic magneto-optical phenomena, awaits to be evidenced in topological insulators. Here, Okada et al. demonstrate Faraday and Kerr rotations of magnetic topological insulator surfaces in quantum anomalous Hall states by terahertz magneto-optics, indicating topological magnetoelectric effect. |
| Databáze: | OpenAIRE |
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