The ambition of the project is to develop and realize conceptually novel and practical quantum limited SQN detector capable to reveal single MW photons for a photon frequency of ~10 GHz with the Heisenberg limit of sensitivity and the quantum limit noise with a view to apply it to the QUAX (QUaerere AXion) experiment, an INFN funded search for galactic axions by means of both ferromagnetic and normal “haloscopes” .
The specific objectives of our project are as follows:
- Development of a single microwave photon detector based on moderate size networks of interacting superconducting qubits utilizing both transmons and flux qubits.
- Development of the Parametric Down Conversion (PDC) microwave photon source based on the Traveling Wave Josephson Parametric Amplifier (TW-JPA) with a clock frequency of few kHz
- Integration of the PDC MW photon source with two single photon SQN detectors in a common setup to develop an heralded single photon source and to carry out the test of the detectors at single MW photons.
- Installation of the single photon SQN detector integrated with the single photon source as a calibration element in a He free refrigerator of the QUAX Collaboration.
- Experimental study of feasibility of the single microwave photon SQN detector for the “haloscope” type of axion searching using the axion conversion in a magnetic field.
 Barbieri et al., Phys. Dark Univ. 15, 135 (2017).
 N. Crescini et al., Eur. Phys. J. C 78, 703 (2018).