The QROCODILE Dark Matter Experiment

Dark matter remains one of the greatest mysteries in modern physics, shaping the cosmos yet evading direct detection. The experiement Quantum Resolution-Optimized Cryogenic Observator for Dark matter Incident at Low Energy (QROCODILE) is a groundbreaking experiment designed to push the boundaries of our search, using advanced superconducting technology to detect the faintest possible interactions.

At the core of QROCODILE are nanowire sensors operating at cryogenic temperatures (SNSPDs), which offer unparalleled sensitivity to energy deposits. By leveraging the unique properties of these detectors, the experiment explores a largely uncharted region of parameter space, probing sub-MeV dark matter interactions that conventional methods struggle to detect.

QROCODILE pioneers the use of SNSPDs as both the target and the sensor for light dark matter (DM).

• It employs a microwire-based WSi SNSPD cooled to 100 mK and biased near its critical current, such that energy deposits from DM scattering or absorption produce measurable pulses
• With a detection threshold of just 112 meV, which corresponds to 11 µm photons,  QROCODILE is sensitive to DM as low as 30 keV, probing unconstrained sub- MeV regime.
• Thanks to its thin-layer geometry with an active area of 600 µm × 600 µm, the detector is  sensitive to incoming particle direction.
• Our SNSPD has demonstrated high internal detection efficiency coupled with low noise.  Still, there are several strategies to improve the sensitivity in the future.