Skip to content

Third-order square-root topological insulators on decorated diamond sonic crystals

MetadataDetails
Publication Date2023-06-26
JournalJournal of Physics Condensed Matter
AuthorsZhi-Guo Geng, Ya‐Xi Shen, Liwei Duan, Zhaojiang Chen, Xue‐Feng Zhu
InstitutionsZhejiang Normal University, Huazhong University of Science and Technology
Citations5

Abstract The square-root operation can generate novel topological phases, whose nontrivial topological properties are inherited from the parent Hamiltonian. Here we report the acoustic realization of third-order square-root topological insulators by adding additional resonators between the site resonators of original diamond lattice. Due to the square-root operation, multiple acoustic localized modes appear in doubled bulk gaps. The bulk polarizations of the tight-binding models are employed to reveal the topological feature of the higher-order topological states. By tuning the coupling strength, we find the emergence of third-order topological corner states in doubled bulk gaps on tetrahedron-like and rhombohedron-like sonic crystals, respectively. The shape dependence of square-root corner states provides an extra degree of freedom for flexible manipulation on the sound localization. Furthermore, the robustness of the corner states in three-dimensional (3D) square-root topological insulator is well elucidated by introducing random disorders into the irrelevant bulk region of the proposed 3D lattices. This work extends square-root higher-order topological states into 3D system, and may find possible applications in selective acoustic sensors.

  1. 2018 - Topological sound [Crossref]
  2. 2019 - Topological phases in acoustic and mechanical systems [Crossref]
  3. 2016 - Acoustic topological insulator and robust one-way sound transport [Crossref]
  4. 2020 - Acoustic analogues of three-dimensional topological insulators [Crossref]
  5. 2020 - Valley-locked waveguide transport in acoustic heterostructures [Crossref]
  6. 2021 - Higher-order band topology [Crossref]
  7. 2021 - Valley-selective topological corner states in sonic crystals [Crossref]
  8. 2021 - Higher-order Dirac sonic crystals [Crossref]
  9. 2022 - Acoustic realization of surface-obstructed topological insulators [Crossref]
  10. 2022 - Design of a higher-order nodal-line semimetal in a spring-shaped acoustic topological crystal [Crossref]