Phononic circuits are emerging devices that can manipulate sound waves (i.e., phonons) in ways that resemble how electronic circuits control the flow of electrons. Phononic circuits are opening new possibilities for the development of high-speed communication systems, quantum information systems and various other technologies. Researchers at University of Science and Technology of China, Penn State University and other institutes recently developed new compact phononic circuits that can reliably guide sound waves at 1.5 GHz. "Our goal was to build tiny, chip-scale phononic circuits operating at GHz frequencies that are compact, reconfigurable, and robust enough for real-world applications." More information: Xin-Biao Xu et al, Gigahertz topological phononic circuits based on micrometre-scale unsuspended waveguide arrays, Nature Electronics (2025).