Observation of an acoustic octupole topological insulator

Berry phase associated with energy bands in crystals can lead to quantised observables like quantised dipole polarizations in one-dimensional topological insulators. Recent theories have generalised the concept of quantised dipoles to multipoles, resulting in the discovery of multipole topological i...

Full description

Saved in:
Bibliographic Details
Main Authors: Xue, Haoran, Ge, Yong, Sun, Hong-Xiang, Wang, Qiang, Jia, Ding, Guan, Yi-Jun, Yuan, Shou-Qi, Chong, Yidong, Zhang, Baile
Other Authors: School of Physical and Mathematical Sciences
Format: Article
Language:English
Published: 2021
Subjects:
Online Access:https://hdl.handle.net/10356/153318
Tags: Add Tag
No Tags, Be the first to tag this record!
Institution: Nanyang Technological University
Language: English
id sg-ntu-dr.10356-153318
record_format dspace
spelling sg-ntu-dr.10356-1533182023-02-28T19:25:44Z Observation of an acoustic octupole topological insulator Xue, Haoran Ge, Yong Sun, Hong-Xiang Wang, Qiang Jia, Ding Guan, Yi-Jun Yuan, Shou-Qi Chong, Yidong Zhang, Baile School of Physical and Mathematical Sciences Centre for Disruptive Photonic Technologies (CDPT) Science::Physics Topological Insulators Acoustics Berry phase associated with energy bands in crystals can lead to quantised observables like quantised dipole polarizations in one-dimensional topological insulators. Recent theories have generalised the concept of quantised dipoles to multipoles, resulting in the discovery of multipole topological insulators which exhibit a hierarchy of multipole topology: a quantised octupole moment in a three-dimensional bulk induces quantised quadrupole moments on its two-dimensional surfaces, which in turn induce quantised dipole moments on one-dimensional hinges. Here, we report on the realisation of an octupole topological insulator in a three-dimensional acoustic metamaterial. We observe zero-dimensional topological corner states, one-dimensional gapped hinge states, two-dimensional gapped surface states, and three-dimensional gapped bulk states, representing the hierarchy of octupole, quadrupole and dipole moments. Conditions for forming a nontrivial octupole moment are demonstrated by comparisons with two different lattice configurations having trivial octupole moments. Our work establishes the multipole topology and its full hierarchy in three-dimensional geometries. Ministry of Education (MOE) Published version H.X., Q.W., Y.C. and B.Z. acknowledge support from Singapore Ministry of Education under grant numbers MOE2018-T2-1-022 (S), MOE2015-T2-2-008, MOE2016-T3-1-006 and Tier 1 RG174/16 (S). Y.G., D.J., Y.-J.G., S.-Q.Y. and H.-X.S. acknowledge support from National Natural Science Foundation of China under grants 11774137 and 51779107. 2021-11-19T07:40:51Z 2021-11-19T07:40:51Z 2020 Journal Article Xue, H., Ge, Y., Sun, H., Wang, Q., Jia, D., Guan, Y., Yuan, S., Chong, Y. & Zhang, B. (2020). Observation of an acoustic octupole topological insulator. Nature Communications, 11(1), 2442-. https://dx.doi.org/10.1038/s41467-020-16350-1 2041-1723 https://hdl.handle.net/10356/153318 10.1038/s41467-020-16350-1 32415220 2-s2.0-85084749280 1 11 2442 en MOE2018-T2-1-022 (S) MOE2015-T2-2-008 Nature Communications 10.21979/N9/94CPSE © 2020 The Author(s). This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/ licenses/by/4.0/. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Science::Physics
Topological Insulators
Acoustics
spellingShingle Science::Physics
Topological Insulators
Acoustics
Xue, Haoran
Ge, Yong
Sun, Hong-Xiang
Wang, Qiang
Jia, Ding
Guan, Yi-Jun
Yuan, Shou-Qi
Chong, Yidong
Zhang, Baile
Observation of an acoustic octupole topological insulator
description Berry phase associated with energy bands in crystals can lead to quantised observables like quantised dipole polarizations in one-dimensional topological insulators. Recent theories have generalised the concept of quantised dipoles to multipoles, resulting in the discovery of multipole topological insulators which exhibit a hierarchy of multipole topology: a quantised octupole moment in a three-dimensional bulk induces quantised quadrupole moments on its two-dimensional surfaces, which in turn induce quantised dipole moments on one-dimensional hinges. Here, we report on the realisation of an octupole topological insulator in a three-dimensional acoustic metamaterial. We observe zero-dimensional topological corner states, one-dimensional gapped hinge states, two-dimensional gapped surface states, and three-dimensional gapped bulk states, representing the hierarchy of octupole, quadrupole and dipole moments. Conditions for forming a nontrivial octupole moment are demonstrated by comparisons with two different lattice configurations having trivial octupole moments. Our work establishes the multipole topology and its full hierarchy in three-dimensional geometries.
author2 School of Physical and Mathematical Sciences
author_facet School of Physical and Mathematical Sciences
Xue, Haoran
Ge, Yong
Sun, Hong-Xiang
Wang, Qiang
Jia, Ding
Guan, Yi-Jun
Yuan, Shou-Qi
Chong, Yidong
Zhang, Baile
format Article
author Xue, Haoran
Ge, Yong
Sun, Hong-Xiang
Wang, Qiang
Jia, Ding
Guan, Yi-Jun
Yuan, Shou-Qi
Chong, Yidong
Zhang, Baile
author_sort Xue, Haoran
title Observation of an acoustic octupole topological insulator
title_short Observation of an acoustic octupole topological insulator
title_full Observation of an acoustic octupole topological insulator
title_fullStr Observation of an acoustic octupole topological insulator
title_full_unstemmed Observation of an acoustic octupole topological insulator
title_sort observation of an acoustic octupole topological insulator
publishDate 2021
url https://hdl.handle.net/10356/153318
_version_ 1759857591077306368