Our new paper titled “Topological dislocation modes in three-dimensional acoustic topological insulators” is published in Nature Communications.
In this work, we experimentally construct a three-dimensional (3D) acoustic topological insulator with precisely-controlled dislocations and present an unambiguous evidence for the long-sought bulk-dislocation correspondence. The delicate design of our acoustic system enables us to observe not only the topological dislocation modes (TDMs) in momentum-resolved frequency spectroscopy but also their spatial localization in pressure-field distributions. The topological robustness of the TDMs is identified by introducing a spin-preserved defect to the dislocation. Significantly, the TDMs observed here exhibit flexibilities in wave manipulations since the dislocation lines can be deformed at will in 3D space. As such, we can design dislocation waveguides of arbitrary shapes and unidirectionally guide the TDMs along any prescribed routes inside the bulk materials, which are conclusively identified by our acoustic experiments.
Our findings will stimulate the study on the highly-intriguing interaction between the real-space topology and band topology. The peculiar topological dislocation transport points to new possibilities for information communication and energy transportation.
Fig. 1. TDMs guided by the dislocations in a 3D topological insulator.
Fig. 2. Numerical demonstrations of the acoustic TDMs and their topological transports.
Fig. 3. Experimental characterizations of the acoustic TDMs and their topological robustness to defects.