Direct Detection of Down-Converted Photons Spontaneously Produced at a Single Josephson Junction
Artikel i vetenskaplig tidskrift, 2025
We study spontaneous photon decay into multiple photons triggered by strong nonlinearities in an experimental simulator of a bosonic quantum impurity model. Previously, spectroscopic signatures of photon conversion were reported and evidenced as resonances in the many-body spectrum of these systems. Here, we report on the observation of multimode fluorescence of a small Josephson junction embedded in a high impedance superconducting transmission line. Measurement of the down-converted photons is achieved using state-of-the-art broadband parametric amplifiers. Photon triplet emission is explicitly demonstrated at a given frequency as the counterpart of inelastic photon decay at 3× the emission frequency. These results open exciting prospects for the burgeoning field of many-body quantum optics and offer a direct signature of the ultrastrong light-matter coupling.
Författare
Dorian Fraudet
Université Grenoble Alpes
Izak Snyman
University of Witwatersrand
Denis M. Basko
Laboratoire de Physique et Modélisation des Milieux Condensés
Sébastien Léger
Stanford University
Université Grenoble Alpes
Théo Sépulcre
Chalmers, Mikroteknologi och nanovetenskap, Tillämpad kvantfysik
Arpit Ranadive
Université Grenoble Alpes
Gwenael Le Gal
Université Grenoble Alpes
Alba Torras-Coloma
Universitat Autonoma de Barcelona (UAB)
Institut de Física d'Altes Energies, Bellaterra
Wiebke Guichard
Université Grenoble Alpes
Serge Florens
Université Grenoble Alpes
Nicolas Roch
Université Grenoble Alpes
Physical Review Letters
0031-9007 (ISSN) 1079-7114 (eISSN)
Vol. 134 1 013804Ämneskategorier (SSIF 2025)
Atom- och molekylfysik och optik
Den kondenserade materiens fysik
Annan fysik
DOI
10.1103/PhysRevLett.134.013804