A deterministic and shape-controlled microwave single-photon source for transduction to optical frequencies

An electro-optic transducer is an essential part of networking superconducting nodes and communicating quantum information from distant places. Our mechanically-mediated electro-optic converter has achieved high efficiency and low added noise [1], and also demonstrates reading out qubits optically [2]. To fit quantum signals within the kHz-scale bandwidth of this transducer, the microwave photon source must be sufficiently coherent. We design a two-post-cavity microwave device for deterministically generating single-photon states and controlling their temporal shape to optimally use the transducer’s bandwidth. Here, I will present our efforts of building up this single-photon source for efficient transduction of microwave photons to optical frequencies.

[1] B. M. Brubaker, J. M. Kindem, M. D. Urmey, S. Mittal, R. D. Delaney, P. S. Burns, M. R. Vissers, K. W. Lehnert, and C. A. Regal. Optomechanical ground-state cooling in a continuous and efficient electro-optic transducer. Phys. Rev. X, 12:021062, Jun 2022.

[2] R. D. Delaney, M. D. Urmey, S. Mittal, B. M. Brubaker, J. M. Kindem, P. S. Burns, C. A. Regal, and K. W. Lehnert. Superconducting-qubit readout via low-backaction electro-optic transduction. Nature, 606(7914):489–493, June 2022.