Topological Phononic Crystals with One-Way Elastic Edge Waves

• Main Authors: Wang, Pai (Author), Lu, Ling (Contributor), Bertoldi, Katia (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), MIT Kavli Institute for Astrophysics and Space Research (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2018-06-26T15:44:04Z.
• Subjects: Article
• Online Access: Get fulltext

We report a new type of phononic crystals with topologically nontrivial band gaps for both longitudinal and transverse polarizations, resulting in protected one-way elastic edge waves. In our design, gyroscopic inertial effects are used to break the time-reversal symmetry and realize the phononic analogue of the electronic quantum (anomalous) Hall effect. We investigate the response of both hexagonal and square gyroscopic lattices and observe bulk Chern numbers of 1 and 2, indicating that these structures support single and multimode edge elastic waves immune to backscattering. These robust one-way phononic waveguides could potentially lead to the design of a novel class of surface wave devices that are widely used in electronics, telecommunication, and acoustic imaging.
National Science Foundation (U.S.) (Grant CMMI-1120724)
National Science Foundation (U.S.) (Grant CMMI-1149456)
National Institutes of Health (U.S.) (Grant DMR-1420570)
United States. Army Research Office (Grant W911NF-13-D-0001)
National Science Foundation (U.S.) (Grant DMR-1419807)