Skip to content

Realization of encircling the exceptional point in non-Hermitian acoustic waveguide coupler

MetadataDetails
Publication Date2025-09-22
JournalApplied Physics Letters
AuthorsJiabao Yao, Cheng Lü, Jianing Zhang, Jie Song, Shuai Tang
InstitutionsHarbin Institute of Technology

The encirclement of exceptional points (EPs) in parametric space has been realized in optical waveguides, microwave cavities, nitrogen-vacancy centers, and so on. However, it often suffers from complex gain-loss manipulation. An acoustic platform to realize the evolution encircling the EP is highly desirable. In this work, an unclosed evolution protocol is proposed, which consists of parallel coupling and buffering branches and evolves through five distinct stages. Buffering the variation of Hamiltonian, inducing the transition to a low energy state, the evolution with favorable adiabaticity guarantees the EP encircling no longer depends on the precise loss manipulation. A non-Hermitian acoustic waveguide coupler (AWC), which is composed of combined cavities and air slit arrays, is presented to realize the encirclement. Experimental results of chiral phase conversion in a 0.5 m long AWC, spanning a broad bandwidth from 9.5 to 17.5 kHz, confirm the simplicity and effectiveness of state evolution encircling the EP. This work paves the way for AWC as a platform for non-Hermitian topological physics and facilitates the practical deployment of acoustic devices.

  1. 2017 - Dynamically encircling exceptional points: Exact evolution and polarization state conversion [Crossref]
  2. 2024 - Exceptional-point-enhanced phase sensing [Crossref]
  3. 2004 - Encircling an exceptional point [Crossref]
  4. 2021 - Dynamically encircling an exceptional point in a real quantum system [Crossref]
  5. 2021 - Topological mode switching in modulated structures with dynamic encircling of an exceptional point [Crossref]
  6. 2018 - Valley physics in non-Hermitian artificial acoustic boron nitride [Crossref]
  7. 2021 - Acoustic non-Hermitian skin effect from twisted winding topology [Crossref]
  8. 2023 - Acoustic chiral mode switching by dynamic encircling of exceptional points [Crossref]
  9. 2024 - Creating anti-chiral exceptional points in non-Hermitian metasurfaces for efficient terahertz switching [Crossref]
  10. 2001 - Experimental observation of the topological structure of exceptional points [Crossref]