2021/04/30 by Haoran Xue, Ding Jia, Yong Ge +6 · 1 citation
Physics and Astronomy · #cond-mat.mes-hall #physics.app-ph
paper · pdf · doi:10.1103/physrevlett.127.214301
published as Phys. Rev. Lett. 127, 214301 (2021) · 6 pages, 4 figures
arxiv created 2021/05/06 · arxiv updated 2021/11/23
The interplay between real-space topological lattice defects and the reciprocal-space topology of energy bands can give rise to novel phenomena, such as one-dimensional topological modes bound to screw dislocations in three-dimensional topological insulators. We obtain direct experimental observations of dislocation-induced helical modes in an acoustic analog of a weak three-dimensional topological insulator. The spatial distribution of the helical modes is found through spin-resolved field mapping, and verified numerically by tight-binding and finite-element calculations. These one-dimensional helical channels can serve as robust waveguides in three-dimensional media. Our experiment paves the way to studying novel physical modes and functionalities enabled by topological lattice defects in three-dimensional classical topological materials.