Tunable topological bandgaps and frequencies in a pre-stressed soft phononic crystal

authored by: B. H. Nguyen, Xiaoying Zhuang, Harold S. Park, Timon Rabczuk
Abstract: Topological insulators (TIs) have recently received significant attention due to the promise of lossless transport of various types of energy. Despite this interest, one outstanding issue is that the topological bandgap and the frequencies that are topologically permitted are typically fixed once the topological structure has been designed and fabricated. Therefore, an open and unresolved question concerns the ability to actively tune both the bandgap magnitude, as well as the frequencies, for which the energy is topologically protected. In this work, we report a mechanically tunable phononic TI using an acoustic analog of the quantum valley Hall effect. We propose a phononic crystal comprised of a soft, hyperelastic material where the phononic band structure is modulated through large deformation of the structure. In doing so, space-inversion symmetry can be broken, which leads to a phase transition between two topologically-contrasted states and the emergence of topologically-protected interface modes according to bulk-edge correspondence. We further demonstrate the robustness of this topological protection of the edge state along the interface, which demonstrates that mechanical deformation can be used to effectively tailor and tune the topological properties of elastic structures.
Organisation(s): Institute of Continuum Mechanics
External Organisation(s): Ton Duc Thang University
Boston University (BU)
Bauhaus-Universität Weimar
Type: Article
Journal: Journal of Applied Physics
Volume: 125
ISSN: 0021-8979
Publication date: 07.03.2019
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: General Physics and Astronomy
Electronic version(s): https://doi.org/10.1063/1.5066088 (Access: Closed)
: Details in the research portal "Research@Leibniz University"

BibTeX

@article{27d314875017466b8552351967992a66,
title = "Tunable topological bandgaps and frequencies in a pre-stressed soft phononic crystal",
abstract = "Topological insulators (TIs) have recently received significant attention due to the promise of lossless transport of various types of energy. Despite this interest, one outstanding issue is that the topological bandgap and the frequencies that are topologically permitted are typically fixed once the topological structure has been designed and fabricated. Therefore, an open and unresolved question concerns the ability to actively tune both the bandgap magnitude, as well as the frequencies, for which the energy is topologically protected. In this work, we report a mechanically tunable phononic TI using an acoustic analog of the quantum valley Hall effect. We propose a phononic crystal comprised of a soft, hyperelastic material where the phononic band structure is modulated through large deformation of the structure. In doing so, space-inversion symmetry can be broken, which leads to a phase transition between two topologically-contrasted states and the emergence of topologically-protected interface modes according to bulk-edge correspondence. We further demonstrate the robustness of this topological protection of the edge state along the interface, which demonstrates that mechanical deformation can be used to effectively tailor and tune the topological properties of elastic structures.",
author = "Nguyen, {B. H.} and Xiaoying Zhuang and Park, {Harold S.} and Timon Rabczuk",
note = "Funding information: B. H. Nguyen and X. Zhuang owe gratitude to the sponsorship from the Sofja Kovalevskaja Programme of Alexander von Humboldt Foundation. H.S.P. acknowledges the support of the Army Research Office (ARO) (Grant No. W911NF-18-1-0380).",
year = "2019",
month = mar,
day = "7",
doi = "10.1063/1.5066088",
language = "English",
volume = "125",
journal = "Journal of Applied Physics",
issn = "0021-8979",
publisher = "American Institute of Physics",
number = "9",
}