Phononic metagrating for lattice wave manipulation

The control of the phonon-wave behavior is of prominent interest for applications in thermal management and the processing of quantum information. In this work, we design and characterize a phonon-based grating nanostructure in a suspended single-layer graphene. The anomalous transmission of lattice waves and the controllable angle of the transmitted wave can be achieved via a skillful design of the underlying nanostructure and the mode conversion can be monitored in situ. An interesting nonlocal effect emerges due to the inherently strong covalent bondings. These features distinctly differ from former scenarios with acoustic waves. This work paves the way for the regulation of phonon transport by designing phonon-based metagrating structures.