TY - JOUR
T1 - Inverse design of quantum spin hall-based phononic topological insulators
AU - Nanthakumar, S. S.
AU - Zhuang, Xiaoying
AU - Park, Harold S.
AU - Nguyen, Chuong
AU - Chen, Yanyu
AU - Rabczuk, Timon
N1 - Funding Information:
HSP acknowledges the support of the Army Research Office , grant W911NF-18-1-0380 .
Publisher Copyright:
© 2019
PY - 2019/4
Y1 - 2019/4
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85060290488&partnerID=8YFLogxK
U2 - 10.1016/j.jmps.2019.01.009
DO - 10.1016/j.jmps.2019.01.009
M3 - Article
AN - SCOPUS:85060290488
SN - 0022-5096
VL - 125
SP - 550
EP - 571
JO - Journal of the Mechanics and Physics of Solids
JF - Journal of the Mechanics and Physics of Solids
ER -