Seminar "Single Microwave-photon detector based on superconducting quantum circuits" by Dr. Kunihiro Inomata, National Institute of Advanced Industrial Science and Technology(AIST)

Speaker: Dr. Kunihiro Inomata, National Institute of Advanced Industrial Science and Technology (AIST)

Title "Single microwave-photon detector based on superconducting quantum circuits"

Abstract:

Single-photon detection is essential to many quantum-optics experiments, enabling photon counting and its statistical and correlational analyses [1]. It is also an indispensable tool in many protocols for quantum communication and quantum information processing [2]. In the optical domain, various kinds of single-photon detectors are commercially available and commonly used [1,3]. However, the detection of a single microwave photon in an itinerant mode remains a challenging task due to its correspondingly small energy.
In this presentation, we demonstrate an efficient and practical single microwave-photon detector based on the deterministic switching in an artificial $\Lambda$-type three-level system implemented using the dressed states of a driven circuit-quantum electrodynamics system [4]. The detector features a high quantum efficiency $0.66 \pm 0.06$, a low dark-count probability $0.014 \pm 0.001$, a bandwidth $\sim 2\pi \times 16$ MHz, and a fast reset time $\sim 400$ ns. The efficiency limited by a relaxation time ($T_1$) of the qubit can readily exceed $0.9$ by improving $T_1$ [5]. Although the detector operates in a time-gated mode, we demonstrate ``continuous" or ``real-time"  detection of itinerant microwave photons by coupling two microwave resonators to a flux qubit.

[1] R. H. Hadfield, Nat. Photon. 3, 696 (2009).
[2] For example, N. Gisin, G. Ribordy, W. Tittel, and H. Zbinden, Rev. Mod. Phys. 74, 145 (2002)
[3] M.D. Eisaman, J. Fan, A. Migdall, and S. V. Polyakov, Rev. Sci. Instrum. 82, 071101 (2011).
[4] K. Inomata, Z.R. Lin, K. Koshino, W.D. Oliver, J.S. Tsai, T. Yamamoto, and Y. Nakamura, Nature Communications 7, 12303 (2016).
[5] K. Koshino, K. Inomata, Z.R. Lin, Y. Nakamura, and T. Yamamoto, Phys. Rev. A 91, 04805 (2015).