Inverse design of quantum spin hall-based phononic topological insulators

authored by
Srivilliputtur Subbiah Nanthakumar, Xiaoying Zhuang, Harold S. Park, Thanh Chuong Nguyen, Yanyu Chen, Timon Rabczuk
Abstract

We propose a computational methodology to perform inverse design of quantum spin hall effect (QSHE)-based phononic topological insulators. We first obtain two-fold degeneracy, or a Dirac cone, in the band structure using a level set-based topology optimization approach. Subsequently, four-fold degeneracy, or a double Dirac cone, is obtained by using zone folding, after which breaking of translational symmetry, which mimics the effect of strong spin-orbit coupling and which breaks the four-fold degeneracy resulting in a bandgap, is applied. We use the approach to perform inverse design of hexagonal unit cells of C 6 and C 3 symmetry. The numerical examples show that a topological domain wall with two variations of the designed metamaterials exhibit topologically protected interfacial wave propagation, and also demonstrate that larger topologically-protected bandgaps may be obtained with unit cells based on C 3 symmetry.

Organisation(s)
Institute of Continuum Mechanics
External Organisation(s)
Tongji University
Dalian University of Technology
Boston University (BU)
University of Louisville
Ton Duc Thang University
King Saud University
Type
Article
Journal
Journal of the Mechanics and Physics of Solids
Volume
125
Pages
550-571
No. of pages
22
ISSN
0022-5096
Publication date
04.2019
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Condensed Matter Physics, Mechanics of Materials, Mechanical Engineering
Electronic version(s)
https://doi.org/10.1016/j.jmps.2019.01.009 (Access: Closed)
 

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