Towards a microwave single-photon counter for searching axions

• Published in: npj quantum information Vol. 8; no. 1; pp. 1 - 7
• Main Authors: Pankratov, A. L., Revin, L. S., Gordeeva, A. V., Yablokov, A. A., Kuzmin, L. S., Il’ichev, E.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 18-05-2022; Nature Publishing Group; Nature Portfolio
• Subjects: 639/766/1130/1064; 639/766/483/3925; Atoms & subatomic particles; Classical and Quantum Gravitation; Efficiency; Photons; Physics; Physics and Astronomy; Quantum Computing; Quantum Field Theories; Quantum Information Technology; Quantum Physics; Relativity Theory; Sensors; Simulation; Spintronics; String Theory
• ISSN: 2056-6387; 2056-6387
• DOI: 10.1038/s41534-022-00569-5

The major task of detecting axions or axion-like particles has two challenges. On the one hand, the ultimate sensitivity is required, down to the energy of a single microwave photon of the yoctojoule range. On the other hand, since the detected events are supposed to be rare, the dark count rate of the detector must be extremely low. We show that this trade-off can be approached due to the peculiar switching dynamics of an underdamped Josephson junction in the phase diffusion regime. The detection of a few photons’ energy at 10 GHz with dark count time above 10 s and the efficiency close to unity was demonstrated. Further enhancements require a detailed investigation of the junction switching dynamics.