Observation of the universal magnetoelectric effect in a 3D topological insulator
Please always quote using this URN: urn:nbn:de:bvb:20-opus-170875
- The electrodynamics of topological insulators (TIs) is described by modified Maxwell’s equations, which contain additional terms that couple an electric field to a magnetization and a magnetic field to a polarization of the medium, such that the coupling coefficient is quantized in odd multiples of α/4π per surface. Here we report on the observation of this so-called topological magnetoelectric effect. We use monochromatic terahertz (THz) spectroscopy of TI structures equipped with a semitransparent gate to selectively address surface states.The electrodynamics of topological insulators (TIs) is described by modified Maxwell’s equations, which contain additional terms that couple an electric field to a magnetization and a magnetic field to a polarization of the medium, such that the coupling coefficient is quantized in odd multiples of α/4π per surface. Here we report on the observation of this so-called topological magnetoelectric effect. We use monochromatic terahertz (THz) spectroscopy of TI structures equipped with a semitransparent gate to selectively address surface states. In high external magnetic fields, we observe a universal Faraday rotation angle equal to the fine structure constant α=e\(^{2}\)/2E\(_{0}\)hc (in SI units) when a linearly polarized THz radiation of a certain frequency passes through the two surfaces of a strained HgTe 3D TI. These experiments give insight into axion electrodynamics of TIs and may potentially be used for a metrological definition of the three basic physical constants.…
Author: | V. Dziom, A. Shuvaev, A. Pimenov, G.V. Astakhov, C. Ames, K. Bendias, J. Böttcher, G. Tkachov, E.M. Hankiewicz, C. Brüne, H. Buhmann, L.W. Molenkamp |
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URN: | urn:nbn:de:bvb:20-opus-170875 |
Document Type: | Journal article |
Faculties: | Fakultät für Physik und Astronomie / Physikalisches Institut |
Fakultät für Physik und Astronomie / Institut für Theoretische Physik und Astrophysik | |
Language: | English |
Parent Title (English): | Nature Communications |
Year of Completion: | 2017 |
Volume: | 8 |
Issue: | 15197 |
Source: | Nature Communications 2017, 8:15197. DOI: 10.1038/ncomms15197 |
DOI: | https://doi.org/10.1038/ncomms15197 |
Pubmed Id: | https://pubmed.ncbi.nlm.nih.gov/28504268 |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik |
Tag: | infrared spectroscopy; topological insulators; topological magnetoelectric effect; topological matter |
Release Date: | 2019/10/14 |
Licence (German): | CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International |