Detection of optical photons from a superconducting qubit*

The ability to convert a superconducting qubit excitation to an optical photon would enable the incorporation of superconducting quantum processors in optical quantum networks. In this talk, we present an integrated device platform for converting a qubit excitation to an optical photon via piezo-optomechanical transduction. We first describe the design and fabrication of a nanomechanical resonator with strong piezoelectric coupling to a transmon qubit and a large optomechanical coupling rate. We then discuss experiments using this mechanical mode as an intermediary to convert a qubit excitation to an optical photon in two steps. First, we dynamically tune the qubit frequency to perform a swap operation between the qubit and the mechanical mode. This is followed by an optical pulse that upconverts the phonon to an optical photon via the optomechanical interaction. We detect the resulting photons and demonstrate optical photon generation from a transmon qubit. We measure qubit Rabi oscillations using single optical photon detection to characterize the transducer’s noise and efficiency. Finally, we discuss prospects for optically mediated entanglement generation between remote superconducting circuits using this platform.

In collaboration with: Alp Sipahigil, Mohammad Mirhosseini, Mahmoud Kalaee, Oskar Painter, Caltech