Practical Single Microwave Photon Counter with $10^\mathrm{-22}$$\mathrm{W/\sqrt{Hz}}$ sensitivity
Résumé
Single photon detection played an important role in the development of quantum optics. Its implementation in the microwave domain is challenging because the photon energy is 5 orders of magnitude smaller. In recent years, significant progress has been made in developing single microwave photon detectors (SMPDs) based on superconducting quantum bits or bolometers. In this paper we present a new practical SMPD based on the irreversible transfer of an incoming photon to the excited state of a transmon qubit by a four-wave mixing process. This device achieves a detection efficiency $\eta = 0.43$ and an operational dark count rate $\alpha = 85$$\mathrm{s^{-1}}$, mainly due to the out-of-equilibrium microwave photons in the input line. The corresponding power sensitivity is $\mathcal{S} = 10^{-22}$$\mathrm{W/\sqrt{Hz}}$, one order of magnitude lower than the state of the art. The detector operates continuously over hour timescales with a duty cycle $\eta_\mathrm{D}=0.84$, and offers frequency tunability of $\sim 400$ MHz around 7 GHz.
Mots clés
photon
energy
qubit
transmon
optics
quantum
detector
microwaves
sensitivity
superconductivity
excited state
4/3
efficiency
bolometer
mixing
Optoelectronics
Quantum information with solid state qubits
Quantum measurement
Quantum sensing
Superconducting qubits
Cavity resonators
Microwave techniques
Single-photon detector