Synthetic Three-DimensionalZ×Z2Topological Insulator in an Elastic Metacrystal,Physical Review Letters

当前位置： X-MOL 学术 › Phys. Rev. Lett. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Synthetic Three-DimensionalZ×Z2Topological Insulator in an Elastic Metacrystal
Physical Review Letters ( IF 8.1 ) Pub Date : 2021-11-17 , DOI: 10.1103/physrevlett.127.214302
Wei Wang ₁ , Ze-Guo Chen ₁ , Guancong Ma ₁

Affiliation

We report a three-dimensional (3D) topological insulator (TI) formed by stacking identical layers of Chern insulators in a hybrid real-synthetic space. By introducing staggered interlayer hopping that respects mirror symmetry, the bulk bands possess an additional

Z_{2}

topological invariant along the stacking dimension, which, together with the nontrivial Chern numbers, endows the system with a

Z \times Z_{2}

topology. A 4-tuple topological index characterizes the system’s bulk bands. Consequently, two distinct types of topological surface modes (TSMs) are found localized on different surfaces. Type-I TSMs are gapless and are protected by Chern numbers, whereas type-II gapped TSMs are protected by

Z_{2}

bulk polarization in the stacking direction. Remarkably, each type-II TSM band is also topologically nontrivial, giving rise to second-order topological hinge modes (THMs). Both types of TSMs and the THMs are experimentally observed in an elastic metacrystal.

中文翻译：