Single microwave-photon detector using an artificial $\Lambda$-type three-level system

TL;DR

This paper demonstrates a highly efficient single microwave-photon detector using an artificial three-level system in a superconducting circuit, achieving a detection efficiency of 66%.

Contribution

It introduces a novel impedance-matched artificial $ ext{Lambda}$ system for microwave photon detection with high efficiency and fast reset time.

Findings

Detection efficiency of 66% achieved.

Reset time of approximately 400 ns.

Potential applications in quantum technologies.

Abstract

Single photon detection is a requisite technique in quantum-optics experiments in both the optical and the microwave domains. However, the energy of microwave quanta are four to five orders of magnitude less than their optical counterpart, making the efficient detection of single microwave photons extremely challenging. Here, we demonstrate the detection of a single microwave photon propagating through a waveguide. The detector is implemented with an "impedance-matched" artificial $\Lambda$ system comprising the dressed states of a driven superconducting qubit coupled to a microwave resonator. We attain a single-photon detection efficiency of $0.66 \pm 0.06$ with a reset time of $\sim 400$~ns. This detector can be exploited for various applications in quantum sensing, quantum communication and quantum information processing.