UltraTopo · Ultra-coherent topological phononic waveguides—towards classical and quantum interconnect

Recent ten years witness great progress on reducing the loss of mechanical resonators by advanced dissipation engineering techniques, which stimulates creation and manipulation of quantum states of mechanical motion for various precise metrology and quantum physics. Furthermore, the mechanical system has shown the potential to enable crucial applications in connecting or mediating separate superconducting qubits and other quantum systems, and distributing information between them. These applications require another mechanical fundamental building block: phononic waveguides, which allow phononic states traveling along confined channels. To date, the loss of the phononic waveguides remains a major limitation preventing them from various applications, especially those in quantum regime. Employing the dissipation engineering techniques to remarkably reduce their propagation loss will greatly enhance their ability for interconnecting or mediating classical and quantum systems, but this have not been investigated yet.In UltraTopo, I will apply the dissipation engineering techniques to topological phononic waveguiding systems to reduce their loss. Topological phononic waveguides are extreme compatible with dissipation engineering due to their crystal structure, and they also provide topologically protected backscattering-immune phonon transport that is crucial for building large phononic networks. I aim to reduce the loss of waveguides to be at least 2 orders of magnitude lower than existing best systems. I will also take this advantage to demonstrate classical and quantum interconnection of two superconducting loop gap resonators separated by centimeters. The project will combine my expertise of topological phononic waveguiding, and expertise of dissipation engineering and quantum electro-/optomechanics from the host group. It will offer new schemes for hybrid quantum systems to many groups and also provide me a unique profile at a new frontier in the field of phononic.