تقرير
Experimental signature of parity anomaly in semi-magnetic topological insulator
| العنوان: | Experimental signature of parity anomaly in semi-magnetic topological insulator |
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| المؤلفون: | Mogi, M., Okamura, Y., Kawamura, M., Yoshimi, R., Yasuda, K., Tsukazaki, A., Takahashi, K. S., Morimoto, T., Nagaosa, N., Kawasaki, M., Takahashi, Y., Tokura, Y. |
| المصدر: | Nature Physics (2022) |
| سنة النشر: | 2021 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science |
| الوصف: | A three-dimensional topological insulator features a two-dimensional surface state consisting of a single linearly-dispersive Dirac cone. Under broken time-reversal symmetry, the single Dirac cone is predicted to cause half-integer quantization of Hall conductance, which is a manifestation of the parity anomaly in quantum field theory. However, despite various observations of quantization phenomena, the half-integer quantization has been elusive because a pair of equivalent Dirac cones on two opposing surfaces are simultaneously measured in ordinary experiments. Here we demonstrate the half-integer quantization of Hall conductance in a synthetic heterostructure termed a 'semi-magnetic' topological insulator, where only one surface state is gapped by magnetic doping and the opposite one is non-magnetic and gapless. We observe half quantized Faraday/Kerr rotations with terahertz magneto-optical spectroscopy and half quantized Hall conductance in transport at zero magnetic field. Our results suggest a condensed-matter realization of the parity anomaly and open a way for studying unconventional physics enabled by a single Dirac fermion. Comment: 25 pages, 7 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1038/s41567-021-01490-y |
| URL الوصول: | http://arxiv.org/abs/2105.04127 |
| رقم الأكسشن: | edsarx.2105.04127 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1038/s41567-021-01490-y |
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