Extended topological mode in a one-dimensional non-Hermitian acoustic crystal

Xulong Wang, Wei Wang, Guancong Ma*

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

2 Citations (Scopus)


In Hermitian topological systems, topological modes (TMs) are bound to interfaces or defects of a lattice. Recent discoveries show that non-Hermitian effects can reshape the wavefunctions of the TMs and even turn them into extended modes occupying the entire bulk lattice. In this letter, we experimentally demonstrate such an extended TM (ETM) in a one-dimensional (1D) non-Hermitian acoustic topological crystal. The acoustic crystal is formed by a series of coupled acoustic resonant cavities, and the non-Hermiticity is introduced as a non-reciprocal coupling coefficient using active electroacoustic controllers (AECs). Our work highlights the potential universality of ETMs in different physical systems and resolves the technical challenges in the further study of ETMs in acoustic waves.

Original languageEnglish
Article number23
JournalAAPPS Bulletin
Issue number1
Publication statusPublished - Dec 2023

Scopus Subject Areas

  • Physics and Astronomy(all)

User-Defined Keywords

  • Acoustics
  • Localization
  • Non-Hermitian systems
  • Phononic crystal
  • Topological modes
  • Topological phases


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