Detection of single-mode thermal microwave photons using an underdamped Josephson junction
Artikel i vetenskaplig tidskrift, 2025

When measuring electromagnetic radiation of frequency f, the most sensitive detector counts single quanta of energy hf. Single photon detectors have been demonstrated from γ-rays to infrared wavelengths, with ongoing efforts to extend their range to microwaves. Here we show that an underdamped Josephson junction can detect 14 GHz thermal photons, with energy 10 yJ or 50 μeV, stochastically emitted by a microwave copper cavity at millikelvin temperatures. After characterizing the source and the detector, we vary the cavity temperature and measure the photon rate. The device achieves 45% efficiency and a dark count rate of 0.1 Hz over several GHz. Demonstrated super-Poissonian photon statistics is a signature of thermal light and a hallmark of quantum chaos. We discuss applications in dark matter axion searches and note its relevance to quantum information and fundamental physics.

Författare

A. L. Pankratov

Nizhny Novgorod State Technical University

Russian Academy of Sciences

A. V. Gordeeva

Nizhny Novgorod State Technical University

A. V. Chiginev

Russian Academy of Sciences

Nizhny Novgorod State Technical University

L. S. Revin

Nizhny Novgorod State Technical University

Russian Academy of Sciences

A. V. Blagodatkin

Russian Academy of Sciences

Nizhny Novgorod State Technical University

Nicolo Crescini

Université Grenoble Alpes

Fondazione Bruno Kessler (FBK)

Leonid Kuzmin

Nizhny Novgorod State Technical University

Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik

Nature Communications

2041-1723 (ISSN) 20411723 (eISSN)

Vol. 16 1 3457

Ämneskategorier (SSIF 2025)

Atom- och molekylfysik och optik

Subatomär fysik

DOI

10.1038/s41467-025-56040-4

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Senast uppdaterat

2025-05-05