Acoustic higher-order topological insulator on a kagome lattice
Higher-order topological insulators1-5 are a family of recently predicted topological phases of matter that obey an extended topological bulk-boundary correspondence principle. For example, a two-dimensional (2D) second-order topological insulator does not exhibit gapless one-dimensional (1D) topolo...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2020
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/138208 |
| _version_ | 1826114145566588928 |
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| author | Xue, Haoran Yang, Yahui Gao, Fei Chong, Yidong Zhang, Baile |
| author2 | School of Physical and Mathematical Sciences |
| author_facet | School of Physical and Mathematical Sciences Xue, Haoran Yang, Yahui Gao, Fei Chong, Yidong Zhang, Baile |
| author_sort | Xue, Haoran |
| collection | NTU |
| description | Higher-order topological insulators1-5 are a family of recently predicted topological phases of matter that obey an extended topological bulk-boundary correspondence principle. For example, a two-dimensional (2D) second-order topological insulator does not exhibit gapless one-dimensional (1D) topological edge states, like a standard 2D topological insulator, but instead has topologically protected zero-dimensional (0D) corner states. The first prediction of a second-order topological insulator1, based on quantized quadrupole polarization, was demonstrated in classical mechanical6 and electromagnetic7,8 metamaterials. Here we experimentally realize a second-order topological insulator in an acoustic metamaterial, based on a 'breathing' kagome lattice9 that has zero quadrupole polarization but a non-trivial bulk topology characterized by quantized Wannier centres2,9,10. Unlike previous higher-order topological insulator realizations, the corner states depend not only on the bulk topology but also on the corner shape; we show experimentally that they exist at acute-angled corners of the kagome lattice, but not at obtuse-angled corners. This shape dependence allows corner states to act as topologically protected but reconfigurable local resonances. |
| first_indexed | 2024-10-01T03:34:42Z |
| format | Journal Article |
| id | ntu-10356/138208 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T03:34:42Z |
| publishDate | 2020 |
| record_format | dspace |
| spelling | ntu-10356/1382082023-02-28T20:04:22Z Acoustic higher-order topological insulator on a kagome lattice Xue, Haoran Yang, Yahui Gao, Fei Chong, Yidong Zhang, Baile School of Physical and Mathematical Sciences Science::Physics Topological Insulators Acoustic Metamaterial Higher-order topological insulators1-5 are a family of recently predicted topological phases of matter that obey an extended topological bulk-boundary correspondence principle. For example, a two-dimensional (2D) second-order topological insulator does not exhibit gapless one-dimensional (1D) topological edge states, like a standard 2D topological insulator, but instead has topologically protected zero-dimensional (0D) corner states. The first prediction of a second-order topological insulator1, based on quantized quadrupole polarization, was demonstrated in classical mechanical6 and electromagnetic7,8 metamaterials. Here we experimentally realize a second-order topological insulator in an acoustic metamaterial, based on a 'breathing' kagome lattice9 that has zero quadrupole polarization but a non-trivial bulk topology characterized by quantized Wannier centres2,9,10. Unlike previous higher-order topological insulator realizations, the corner states depend not only on the bulk topology but also on the corner shape; we show experimentally that they exist at acute-angled corners of the kagome lattice, but not at obtuse-angled corners. This shape dependence allows corner states to act as topologically protected but reconfigurable local resonances. 2020-04-29T02:52:11Z 2020-04-29T02:52:11Z 2019 Journal Article Xue, H., Yang, Y., Gao, F., Chong, Y., & Zhang, B. (2019). Acoustic higher-order topological insulator on a kagome lattice. Nature Materials, 18(2), 108-112. doi:10.1038/s41563-018-0251-x 1476-1122 https://hdl.handle.net/10356/138208 10.1038/s41563-018-0251-x 30598539 2-s2.0-85059454458 2 18 108 112 en Nature Materials 10.21979/N9/HRV6VD application/pdf |
| spellingShingle | Science::Physics Topological Insulators Acoustic Metamaterial Xue, Haoran Yang, Yahui Gao, Fei Chong, Yidong Zhang, Baile Acoustic higher-order topological insulator on a kagome lattice |
| title | Acoustic higher-order topological insulator on a kagome lattice |
| title_full | Acoustic higher-order topological insulator on a kagome lattice |
| title_fullStr | Acoustic higher-order topological insulator on a kagome lattice |
| title_full_unstemmed | Acoustic higher-order topological insulator on a kagome lattice |
| title_short | Acoustic higher-order topological insulator on a kagome lattice |
| title_sort | acoustic higher order topological insulator on a kagome lattice |
| topic | Science::Physics Topological Insulators Acoustic Metamaterial |
| url | https://hdl.handle.net/10356/138208 |
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