Universal Role of Combined Symmetry for the Protection of the Dirac Cone in Antiferromagnetic Topological Insulators
| Autor: | Honma, Asuka, Kabeya, Noriyuki, Souma, Seigo, Wang, Yongjian, Yamauchi, Kunihiko, Nakayama, Kosuke, Takane, Daichi, Ozawa, Kenichi, Kitamura, Miho, Horiba, Koji, Kumigashira, Hiroshi, Oguchi, Tamio, Takahashi, Takashi, Kimura, Noriaki, Ando, Yoichi, Sato, Takafumi |
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| Rok vydání: | 2024 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | Antiferromagnetic topological insulators (AF TIs) are predicted to exhibit exotic physical properties such as gigantic optical and topological magnetoelectric responses. While a key to achieving such phenomena relies on how to break the symmetry protecting the Dirac-cone surface state (SS) and acquire the mass of Dirac fermions, the mechanism has yet to be clarified. To address this issue, we carried out micro-focused angle-resolved photoemission spectroscopy for GdBi hosting the type-II AF order, and uncovered the stripe-type 2$\times$1 reconstruction of the Fermi surface associated with the AF band folding. Intriguingly, in contrast to NdBi with the type-I AF order displaying the surface-selective Dirac-fermion mass, GdBi shows massless behavior irrespective of AF domains due to the robust topological protection. These results strongly suggest a crucial role of the ThetaTD (time-reversal and translational) symmetry to create the Dirac-fermion mass in AF TIs. Comment: 18 pages, 5 figures |
| Databáze: | arXiv |
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