Quantum light detection in high- temperature superconducting nanowires

Abstract

Detection of light quanta in superconducting nano- and microwires is the key enabling technology for fields ranging from quantum optics and quantum photonics to emerging applications like dark matter searches. However, recent progress in accessing lower photon energies or utilizing high-temperature superconductors reveals substantial gaps in understanding quantum detection physics and calibrating photonic quantum systems. To bridge these gaps, we develop a universal model that incorporates spatially and energy-resolved detection physics, essential for photonic quantum sensors. We validate our approach using modern MgB2 nanowire detectors, retrieving their detection threshold and its intrinsic energy blur, by disentangling the complex statistics of single- and multiphoton detection. Our model can augment quantum detector tomography by embedding physical constraints, and it offers a practical tool for modeling and engineering a broad class of detectors under diverse operating conditions.