Speakers
Description
Axions are hypothetical particles proposed to solve the strong CP problem in QCD and are among the most compelling candidates for dark matter. The RADES (Relic Axion Detector Experimental Setup) collaboration is dedicated to axion searches through the development of innovative haloscope detectors, a well-established technique that exploits axion–photon conversion in strong magnetic fields.
Current efforts focus on integrating quantum sensing technologies to substantially enhance detection sensitivity. Within the DarkQuantum ERC Synergy Grant, RADES researchers are developing quantum sensors based on superconducting transmon qubits for axion searches. In the node at ENS Paris, we are developing an experimental prototype using a granular aluminium transmon coupled to a microwave cavity. The novelty of our system lies in its ability to detect the phase shift induced by the coherent signal generated through axion–photon conversion. The intrinsic anharmonicity of the superconducting circuit significantly enhances sensitivity to extremely weak signals. Calibration with weak coherent tones has demonstrated sensitivities down to n∼10^−5 photons, and a dedicated calibration source has been developed to emulate the random initial phase of the axion signal with a coherence time of the order of hundreds of us, consistent with the expected axion linewidth due to the velocity dispersion of dark matter in the Galactic halo.
| Main Contribution topic | Axion / Sterile |
|---|---|
| Secondary contribution topic | Direct detection |