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

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

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

26 Citations (Scopus)


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
Pages (from-to)1740-1745
Number of pages6
JournalScience Bulletin
Issue number17
Early online date15 May 2021
Publication statusPublished - 15 Sept 2021

Scopus Subject Areas

  • General

User-Defined Keywords

  • 3D acoustic interferometer
  • Higher-order topological insulator
  • Negative refraction
  • Topological states


Dive into the research topics of 'Multi-dimensional wave steering with higher-order topological phononic crystal'. Together they form a unique fingerprint.

Cite this