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A proposal of strong and weak phases in second-order topological insulators
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| Title: | A proposal of strong and weak phases in second-order topological insulators |
| Authors: | Komori, Shiryu Browse this author | | Kondo, Kenji Browse this author →KAKEN DB |
| Keywords: | topological insulators | | higher-order topological insulators | | Wilson loop | | bulk-corner correspondence |
| Issue Date: | Dec-2020 |
| Publisher: | IOP Publishing |
| Journal Title: | Journal of Physics Communications |
| Volume: | 4 |
| Issue: | 12 |
| Start Page: | 125005 |
| Publisher DOI: | 10.1088/2399-6528/abd0d4 |
| Abstract: | Recently, it has been discovered theoretically that there exist novel types of 3-dimensional topological insulators (TIs) whose gapless states manifest themselves at 1-dimensional hinges. They are called second-order topological insulators (SOTIs). Most mathematical models of SOTIs compose of conventional strong topological insulators (STIs) and additional mass terms In this paper, we investigate whether the models made based on weak topological insulators (WTIs) can have hinge states as the same as those made based on the STIs. We found that the models based on WTIs have only trivial Z(2) index determined by the Wilson loop formalism unlike the models based on STIs. However, they can be regarded as stacking of 2-dimensional SOTIs along the z direction. Thus, we propose that there are topologically three different phases in our considering system: ordinary insulator, strong SOTI, and weak SOTI phases. This classification suggests the existence of other topological invariants besides the Z(2) index. Finally, we propose new indices which can distinguish weak SOTIs from ordinary insulators. |
| Rights: | https://creativecommons.org/licenses/by/4.0/ |
| Type: | article |
| URI: | http://hdl.handle.net/2115/80255 |
| Appears in Collections: | 電子科学研究所 (Research Institute for Electronic Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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