Back to Search
Start Over
Demonstration of a quantized acoustic octupole topological insulator.
- Source :
- Nature Communications; 4/30/2020, Vol. 11 Issue 1, p1-7, 7p
- Publication Year :
- 2020
-
Abstract
- Recently introduced quantized multipole topological insulators (QMTIs) reveal new types of gapped boundary states, which themselves represent lower-dimensional topological phases and host symmetry protected zero-dimensional corner states. Inspired by these predictions, tremendous efforts have been devoted to the experimental observation of quantized quadrupole topological phase. However, due to stringent requirements of anti-commuting reflection symmetries, it is challenging to achieve higher-order quantized multipole moments, such as octupole moments, in a three-dimensional structure. Here, we overcome this challenge, and experimentally realize the acoustic analogue of a quantized octupole topological insulator using negatively coupled resonators. We confirm by first-principle studies that our design possesses a quantized octupole topological phase, and experimentally demonstrate spectroscopic evidence of a hierarchy of boundary modes, observing 3<superscript>rd</superscript> order topological corner states. Furthermore, we reveal topological phase transitions from higher- to lower-order multipole moments. Our work offers a pathway to explore higher-order topological states in 3D classical platforms. Although multipole topological insulators have been theoretically described and experimentally observed in 2D, third-order topological insulators in 3D have not been observed yet. Here, the authors realize for the first time a quantized octupole 3D topological state in an acoustic metamaterial. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 20411723
- Volume :
- 11
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Nature Communications
- Publication Type :
- Academic Journal
- Accession number :
- 142999512
- Full Text :
- https://doi.org/10.1038/s41467-020-15705-y