Topological acoustic delay line Articles uri icon

publication date

  • March 2018

start page

  • 1

end page

  • 11

issue

  • 3 (034032)

volume

  • 9

International Standard Serial Number (ISSN)

  • 2331-7019

abstract

  • Topological protected wave engineering in artificially structured media is at the frontier of ongoing metamaterials research that is inspired by quantum mechanics. Acoustic analogues of electronic topological insulators have recently led to a wealth of new opportunities in manipulating sound propagation with strikingly unconventional acoustic edge modes immune to backscattering. Earlier fabrications of topological insulators are characterized by an unreconfigurable geometry and a very narrow frequency response, which severely hinders the exploration and design of useful devices. Here we establish topologically protected sound in reconfigurable phononic crystals that can be switched on and off simply by rotating its three-legged "atoms" without altering the lattice structure. In particular, we engineer robust phase delay defects that take advantage of the ultrabroadband reflection-free sound propagation. Such topological delay lines serve as a paradigm in compact acoustic devices, interconnects, and electroacoustic integrated circuits.

keywords

  • Acoustic wave phenomena
    Edge states
    Topological insulators
    Acoustic metamaterials
    Functional materials
    Sound wave techniques