2-bit topological-encoded acoustic multifunctional device

TL;DR

This paper introduces a novel 2-bit topological-encoded acoustic device that enables simultaneous multi-band control of valley-projected edge states, advancing multifunctional acoustic signal processing.

Contribution

It presents a theoretical and experimental study of a binary topological-encoded acoustic valley-Hall insulator for multi-band, individually controllable edge states, enabling new multifunctional acoustic devices.

Findings

Successful experimental demonstration of dual-band valley-projected edge states.

Design of three proof-of-concept devices: frequency beam splitter, demultiplexer, and whispering gallery.

Enhanced capabilities for multi-channel acoustic signal processing and memory.

Abstract

Valley degree of freedom, an excellent information carrier in valleytronics, has been further introduced into advanced microstructure systems for achieving the acoustic valley-Hall topological insulators (VHTIs), which host valley-projected edge states suppressing the undesired sound backscattering under certain perturbations. Therein, the majority of previous literatures focused on single frequency region, and the lack of capability of simultaneous multi-band operation with individual control radically impedes their potential applications. Here, a binary topological-encoded acoustic VHTI is investigated both theoretically and experimentally to manipulate each of the dual-band valley-projected edge states. Through arranging different coding elements derived from the combined valley-Chern numbers, the existence and propagation directions of the frequency selective edge states can be configured in corresponding frequency regions individually. On this basis, three types of proof-of-concept acoustic topological-encoded functional devices are designed, including frequency beam splitter, anti-interference demultiplex topological sensing and composite topological whispering gallery. Our proposal may provide versatile possibilities for achieving the integrated multifunctional systems in multi-channel signal processing and memorizing with high efficiency and high capacity.