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Updated: Jan 8, 2026
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
Non-uniform square-octagon lattice: a new platform for quantum spin Hall insulator
Jun Hong Wei1, Guo Xiang Wang1
1School of Science, Henan Institute of Technology, 453003 XinXiang, People's Republic of China.
None:
The tight-binding model of the non-uniform square-octagon lattice is investigated, with two kinds of spin-orbit couplings denoted asλso1andλso2. The topological invariantZ2is evaluated numerically using the Fukui-Hatsugai method. A comprehensive analysis is conducted on the influence of two spin-orbit couplingsλso1andλso2on the electronic band structure and the associated topological phase transition. Bothλso1andλso2are observed to induce band gap closure and reopening, indicative of topological phase transition. In particular, at 1/8 and 3/8 filling fractions, the spin-orbit couplingλso1drives the system into a quantum spin Hall (QSH) phase. In contrast,λso2only stabilizes the QSH phase at 3/8 filling. The presence of topologically protected edge state is further verified, providing robust evidence of the nontrivial topological character of the system. These findings demonstrate that the non-uniform square-octagon lattice can serve as a promising platform for realizing nontrivial topological phases, expanding the family of two-dimensional materials capable of hosting the QSH effect.
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