Wang, PaiLu, LingBertoldi, Katia2017-08-072015Wang, Pai, Ling Lu, and Katia Bertoldi. 2015. “Topological Phononic Crystals with One-Way Elastic Edge Waves.” Physical Review Letters 115 (10) (September). doi:10.1103/physrevlett.115.104302.0031-9007http://nrs.harvard.edu/urn-3:HUL.InstRepos:33719363We report a new type of phononic crystals with topologically non-trivial bandgaps 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 Hall effect. We investigate the response of both hexagonal and square gyroscopic lattices and observe bulk Chern number of 1 and 2, indicating that these structures support single and multi-mode edge elastic waves immune to back-scattering. 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.en-USJournal Article2017-08-0710.1103/PhysRevLett.115.104302