Microwave-to-optical quantum frequency conversion with thin-film lithium niobate on silicon-on-insulator piezo-optomechanics*

Interconnecting superconducting quantum processors is an important step towards large-scale quantum computing and the quantum internet. The cryogenic environment poses harsh challenges on the efficiency and scale of interconnections at microwave frequencies. Microwave-to-optical quantum frequency conversion enables the low loss telecommunication channels for potentially high bandwidth and long distance quantum links between superconducting qubits. This has motivated development of converters with low energy consumption and high efficiency for practical applications. Here we demonstrate our recent progress on the piezo-optomechanical approach of the microwave-to-optical quantum frequency conversion by combining state-of-the-art silicon optomechanics with thin-film lithium niobate piezoelectric resonators. We will present our design and fabrication of the converter, and characterization of the efficient piezo-optomechanical coupling and frequency conversion at room temperature and in dilution fridge environment. Our device paves the way towards low-energy, low-noise conversion between microwave and optical photons, as well as generation and manipulation of microwave quantum states using optical frequency quantum techniques.