中国物理B ›› 2020, Vol. 29 ›› Issue (10): 106301-.doi: 10.1088/1674-1056/abad21

• • 上一篇    下一篇

Yan Li(李妍)1,†(), Yi-Nuo Liu(刘一诺)1, Xia Zhang(张霞)1   

  • 收稿日期:2020-07-02 修回日期:2020-07-30 接受日期:2020-08-07 出版日期:2020-10-05 发布日期:2020-10-05
  • 通讯作者: Yan Li(李妍)

Acoustic topological phase transition induced by band inversion of high-order compound modes and robust pseudospin-dependent transport

Yan Li(李妍)†, Yi-Nuo Liu(刘一诺), and Xia Zhang(张霞)   

  1. 1 School of Physics and Physical Engineering, Qufu Normal University, Qufu 273165, China
  • Received:2020-07-02 Revised:2020-07-30 Accepted:2020-08-07 Online:2020-10-05 Published:2020-10-05
  • Contact: Corresponding author. E-mail: liyanQFNU@163.com
  • About author:
    †Corresponding author. E-mail: liyanQFNU@163.com
    * Project supported by the Young Scientists Fund of the Natural Science Foundation of Shandong Province, China (Grant No. ZR2016AQ09) and Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 11704219).

Abstract:

A simple two-dimensional phononic crystal hosting topologically protected edge states is proposed to emulate the quantum spin Hall effect in electronic systems, whose phononic topological phase can be reconfigured through the rotation of scatters. In particular, the band inversion occurs between two pairs of high-order compound states, resulting in topological phase transition from trivial to nontrivial over a relatively broad high-frequency range. This is further evidenced by an effective Hamiltonian derived by the kp perturbation theory. The phononic topology is related to a pseudo-time-reversal symmetry constructed by the point group symmetry of two doubly degenerate eigenstates. Numerical simulations unambiguously demonstrate robust helical edge states whose pseudospin indices are locked to the propagation direction along the interface between topologically trivial and nontrivial phononic crystals. Our designed phononic systems provide potential applications in robust acoustic signal transport along any desired path over a high-frequency range.

Key words: topological phase transition, band inversion, compound mode, pseudospin

中图分类号:  (Phonons in crystal lattices)

  • 63.20.-e
43.35.Gk (Phonons in crystal lattices, quantum acoustics) 43.40.+s (Structural acoustics and vibration) 46.40.-f (Vibrations and mechanical waves)