1B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Nauky Ave., Kharkiv 61103, Ukraine
2The Northwest China Research Institute of Electronic Equipment (NWIEE), No.30, Zhangba Sanlu, Xi'an, Shaanxi, 710065, China
3National Science Center “Kharkov Institute of Physics and Technology” 1 Akademicheskaya Str., Kharkov 61108, Ukrain
Received November 2, 2017
Various types of single photon counters operating in infrared, ultraviolet and optical wavelength range are successfully used for exploring electromagnetic fields, radiation source analysis and solving problems of quantum informatics. However, in millimeter, centimeter and decimeter wavelength range their operation principles become ineffective since the quantum energy is 4–5 orders of magnitude lower. Josephson circuits with discrete Hamiltonians and qubits are a good base for constructing single photon counters at these frequencies. In the paper frequency-tuned counters of microwave photons are considered based on a superconductive single-junction interferometer and a flux qutrit. The control pulse turns the interferometer into a two-level system capable of resonant absorbing the microwave photon. The decay of the photon-induced excited state changes magnetic flux in the interferometer that is measured by a SQUID magnetomer. The readout circuits of the mag-netic flux are discussed including a dc SQUID or an ideal parametric detector based on an rf-driven qutrit. It is shown that the counter based on the interferometer with a Josephson junction and the parametric detector demonstrates high performance rate and is capable of detecting single photons in microwave wavelength range.
PACS: 03.67.Hk Quantum communication; PACS: 07.20.Mc Cryogenics; refrigerators, low-temperature detectors, and other low-temperature equipment; PACS: 85.25.Dq Superconducting quantum interference devices (SQUIDs); PACS: 85.25.Pb Superconducting infrared, submillimeter and millimeter wave detectors.