Work

Stroboscopic detection of itinerant microwave photons

Year: 2026

Type: article

Abstract: We present a scheme to detect itinerant microwave radiation at the single photon level. Using existing Josephson-photonics devices, where two microwave cavities are coupled by a dc-voltage-biased superconducting junction, we theoretically show how to implement a stroboscopically repeated, near-projective measurement of a photon impinging on one of the cavities. Optimizing rate, duration, and strength of the measurement by flux control of the junction and developing a threshold protocol to detect the photon from a homodyne measurement of the radiation output of the other cavity, we achieve highly efficient detection with low dark counts. By cascading the detector with a preamplifier, where a similar two-cavity Josephson-photonics device acts as a photon multiplier, we can further improve the device to reach a detection efficiency of 88.5 % with a dark count rate of ∼ 10 − 4 γ a , set by the resonance width γ a of the absorbing cavity. These results for a preamplification factor of 2 suggest that higher preamplification factors may yield near-unity efficiencies.

Source: Physical Review Research

DOI: 10.1103/xnm9-98cm

Authors: Hanna Zeller, Lukas Danner, Max Hofheinz, Ciprian Padurariu, Joachim Ankerhold, Björn Kubala

Institutions: Universität Ulm, Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR), Université de Sherbrooke

Language: English

Topic: Quantum Information and Cryptography

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,625

Funders: Deutsche Forschungsgemeinschaft, Bundesministerium für Bildung und Forschung, Natural Sciences and Engineering Research Council of Canada