Average symmetry protected higher-order topological amorphous insulators
While topological phases have been extensively studied in amorphous systems in recent years, it remains unclear whether the random nature of amorphous materials can give rise to higher-order topological phases that have no crystalline counterparts. Here we theoretically demonstrate the existence of...
| Main Author: | |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
SciPost
2023-11-01
|
| Series: | SciPost Physics |
| Online Access: | https://scipost.org/SciPostPhys.15.5.193 |
| _version_ | 1827762663692697600 |
|---|---|
| author | Yu-Liang Tao, Jiong-Hao Wang, Yong Xu |
| author_facet | Yu-Liang Tao, Jiong-Hao Wang, Yong Xu |
| author_sort | Yu-Liang Tao, Jiong-Hao Wang, Yong Xu |
| collection | DOAJ |
| description | While topological phases have been extensively studied in amorphous systems in recent years, it remains unclear whether the random nature of amorphous materials can give rise to higher-order topological phases that have no crystalline counterparts. Here we theoretically demonstrate the existence of higher-order topological insulators in two-dimensional amorphous systems that can host more than six corner modes, such as eight or twelve corner modes. Although individual sample configuration lacks crystalline symmetry, we find that an ensemble of all configurations exhibits an average crystalline symmetry that provides protection for the new topological phases. To characterize the topological phases, we construct two topological invariants. Even though the bulk energy gap in the topological phase vanishes in the thermodynamic limit, we show that the bulk states near zero energy are localized, as supported by the level-spacing statistics and inverse participation ratio. Our findings open an avenue for exploring average symmetry protected higher-order topological phases in amorphous systems without crystalline counterparts. |
| first_indexed | 2024-03-11T10:33:47Z |
| format | Article |
| id | doaj.art-a6cc1e20ccb54cd8a425301e368df925 |
| institution | Directory Open Access Journal |
| issn | 2542-4653 |
| language | English |
| last_indexed | 2024-03-11T10:33:47Z |
| publishDate | 2023-11-01 |
| publisher | SciPost |
| record_format | Article |
| series | SciPost Physics |
| spelling | doaj.art-a6cc1e20ccb54cd8a425301e368df9252023-11-14T12:38:58ZengSciPostSciPost Physics2542-46532023-11-0115519310.21468/SciPostPhys.15.5.193Average symmetry protected higher-order topological amorphous insulatorsYu-Liang Tao, Jiong-Hao Wang, Yong XuWhile topological phases have been extensively studied in amorphous systems in recent years, it remains unclear whether the random nature of amorphous materials can give rise to higher-order topological phases that have no crystalline counterparts. Here we theoretically demonstrate the existence of higher-order topological insulators in two-dimensional amorphous systems that can host more than six corner modes, such as eight or twelve corner modes. Although individual sample configuration lacks crystalline symmetry, we find that an ensemble of all configurations exhibits an average crystalline symmetry that provides protection for the new topological phases. To characterize the topological phases, we construct two topological invariants. Even though the bulk energy gap in the topological phase vanishes in the thermodynamic limit, we show that the bulk states near zero energy are localized, as supported by the level-spacing statistics and inverse participation ratio. Our findings open an avenue for exploring average symmetry protected higher-order topological phases in amorphous systems without crystalline counterparts.https://scipost.org/SciPostPhys.15.5.193 |
| spellingShingle | Yu-Liang Tao, Jiong-Hao Wang, Yong Xu Average symmetry protected higher-order topological amorphous insulators SciPost Physics |
| title | Average symmetry protected higher-order topological amorphous insulators |
| title_full | Average symmetry protected higher-order topological amorphous insulators |
| title_fullStr | Average symmetry protected higher-order topological amorphous insulators |
| title_full_unstemmed | Average symmetry protected higher-order topological amorphous insulators |
| title_short | Average symmetry protected higher-order topological amorphous insulators |
| title_sort | average symmetry protected higher order topological amorphous insulators |
| url | https://scipost.org/SciPostPhys.15.5.193 |
| work_keys_str_mv | AT yuliangtaojionghaowangyongxu averagesymmetryprotectedhigherordertopologicalamorphousinsulators |