Measurement of Corner-Mode Coupling in Acoustic Higher-Order Topological Insulators
Recent developments of band topology have revealed a variety of higher-order topological insulators (HOTIs). These HOTIs are characterized by a variety of different topological invariants, making them different at a fundamental level. However, despite such differences, the fact that they all sustain...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2021-10-01
|
| Series: | Frontiers in Physics |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fphy.2021.770589/full |
| _version_ | 1828957508785405952 |
|---|---|
| author | Xiao Li Xiao Li Xiao Li Shiqiao Wu Guanqing Zhang Wanzhu Cai Jack Ng Guancong Ma |
| author_facet | Xiao Li Xiao Li Xiao Li Shiqiao Wu Guanqing Zhang Wanzhu Cai Jack Ng Guancong Ma |
| author_sort | Xiao Li |
| collection | DOAJ |
| description | Recent developments of band topology have revealed a variety of higher-order topological insulators (HOTIs). These HOTIs are characterized by a variety of different topological invariants, making them different at a fundamental level. However, despite such differences, the fact that they all sustain higher-order topological boundary modes poses a challenge to phenomenologically tell them apart. This work presents experimental measurements of the coupling effects of topological corner modes (TCMs) existing in two different types of two-dimensional acoustic HOTIs. Although both HOTIs have a similar four-site square lattice, the difference in magnetic flux per unit cell dictates that they belong to different types of topologically nontrivial phases—one lattice possesses quantized dipole moments, but the other is characterized by quantized quadrupole moment. A link between the topological invariants and the response line shape of the coupled TCMs is theoretically established and experimentally confirmed. Our results offer a pathway to distinguish HOTIs experimentally. |
| first_indexed | 2024-12-14T08:30:06Z |
| format | Article |
| id | doaj.art-3b6a918d93fc46b3aa8ce78a8d5e69c8 |
| institution | Directory Open Access Journal |
| issn | 2296-424X |
| language | English |
| last_indexed | 2024-12-14T08:30:06Z |
| publishDate | 2021-10-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Physics |
| spelling | doaj.art-3b6a918d93fc46b3aa8ce78a8d5e69c82022-12-21T23:09:32ZengFrontiers Media S.A.Frontiers in Physics2296-424X2021-10-01910.3389/fphy.2021.770589770589Measurement of Corner-Mode Coupling in Acoustic Higher-Order Topological InsulatorsXiao Li0Xiao Li1Xiao Li2Shiqiao Wu3Guanqing Zhang4Wanzhu Cai5Jack Ng6Guancong Ma7Department of Physics, Southern University of Science and Technology, Shenzhen, ChinaDepartment of Physics, Hong Kong Baptist University, Kowloon Tong, ChinaDepartment of Physics, The Hong Kong University of Science and Technology, Hong Kong, ChinaDepartment of Physics, Hong Kong Baptist University, Kowloon Tong, ChinaDepartment of Physics, Hong Kong Baptist University, Kowloon Tong, ChinaGuangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Siyuan Laboratory, Department of Physics, Jinan University, Guangzhou, ChinaDepartment of Physics, Southern University of Science and Technology, Shenzhen, ChinaDepartment of Physics, Hong Kong Baptist University, Kowloon Tong, ChinaRecent developments of band topology have revealed a variety of higher-order topological insulators (HOTIs). These HOTIs are characterized by a variety of different topological invariants, making them different at a fundamental level. However, despite such differences, the fact that they all sustain higher-order topological boundary modes poses a challenge to phenomenologically tell them apart. This work presents experimental measurements of the coupling effects of topological corner modes (TCMs) existing in two different types of two-dimensional acoustic HOTIs. Although both HOTIs have a similar four-site square lattice, the difference in magnetic flux per unit cell dictates that they belong to different types of topologically nontrivial phases—one lattice possesses quantized dipole moments, but the other is characterized by quantized quadrupole moment. A link between the topological invariants and the response line shape of the coupled TCMs is theoretically established and experimentally confirmed. Our results offer a pathway to distinguish HOTIs experimentally.https://www.frontiersin.org/articles/10.3389/fphy.2021.770589/fulltopological corner modeshigher-order topological insulatorsphononic crystalstightbinding modelgreen’s function |
| spellingShingle | Xiao Li Xiao Li Xiao Li Shiqiao Wu Guanqing Zhang Wanzhu Cai Jack Ng Guancong Ma Measurement of Corner-Mode Coupling in Acoustic Higher-Order Topological Insulators Frontiers in Physics topological corner modes higher-order topological insulators phononic crystals tightbinding model green’s function |
| title | Measurement of Corner-Mode Coupling in Acoustic Higher-Order Topological Insulators |
| title_full | Measurement of Corner-Mode Coupling in Acoustic Higher-Order Topological Insulators |
| title_fullStr | Measurement of Corner-Mode Coupling in Acoustic Higher-Order Topological Insulators |
| title_full_unstemmed | Measurement of Corner-Mode Coupling in Acoustic Higher-Order Topological Insulators |
| title_short | Measurement of Corner-Mode Coupling in Acoustic Higher-Order Topological Insulators |
| title_sort | measurement of corner mode coupling in acoustic higher order topological insulators |
| topic | topological corner modes higher-order topological insulators phononic crystals tightbinding model green’s function |
| url | https://www.frontiersin.org/articles/10.3389/fphy.2021.770589/full |
| work_keys_str_mv | AT xiaoli measurementofcornermodecouplinginacoustichigherordertopologicalinsulators AT xiaoli measurementofcornermodecouplinginacoustichigherordertopologicalinsulators AT xiaoli measurementofcornermodecouplinginacoustichigherordertopologicalinsulators AT shiqiaowu measurementofcornermodecouplinginacoustichigherordertopologicalinsulators AT guanqingzhang measurementofcornermodecouplinginacoustichigherordertopologicalinsulators AT wanzhucai measurementofcornermodecouplinginacoustichigherordertopologicalinsulators AT jackng measurementofcornermodecouplinginacoustichigherordertopologicalinsulators AT guancongma measurementofcornermodecouplinginacoustichigherordertopologicalinsulators |