Multi-dimensional wave steering with higher-order topological phononic crystal

Changqing Xu, Ze-Guo Chen, Guanqing Zhang, Guancong Ma, Ying Wu

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


The recent discovery and realizations of higher-order topological insulators enrich the fundamental studies on topological phases. Here, we report three-dimensional (3D) wave-steering capabilities enabled by topological boundary states at three different orders in a 3D phononic crystal with nontrivial bulk topology originated from the synergy of mirror symmetry of the unit cell and a non-symmorphic glide symmetry of the lattice. The multitude of topological states brings diverse possibilities of wave manipulations. Through judicious engineering of the boundary modes, we experimentally demonstrate two functionalities at different dimensions: 2D negative refraction of sound wave enabled by a first-order topological surface state with negative dispersion, and a 3D acoustic interferometer leveraging on second-order topological hinge states. Our work showcases that topological modes at different orders promise diverse wave steering applications across different dimensions.
Original languageEnglish (US)
JournalScience Bulletin
StatePublished - May 15 2021

Bibliographical note

KAUST Repository Item: Exported on 2021-06-09
Acknowledged KAUST grant number(s): BAS/1/1626-01-01, OSR-2016-CRG5-2950
Acknowledgements: Ying Wu was supported by the King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR) under Award No. OSR-2016-CRG5-2950 and KAUST Baseline Research Fund BAS/1/1626-01-01. Guancong Ma was supported by the Hong Kong Research Grants Council (GRF 12302420, 12300419, ECS 22302718, CRF C6013-18G), the National Natural Science Foundation of China via the Excellent Young Scientist Scheme (Hong Kong & Macao) (#11922416) and the Youth Program (#11802256), and Hong Kong Baptist University (RC-SGT2/18-19/SCI/006).

ASJC Scopus subject areas

  • General


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