Roman Sobolewski: Superconducting single-photon detectors twenty plus years

HyperComplex Seminar 2024 Roman Sobolewski, University of Rochester (Rochester, USA) Abstract. Since their invention in 2001, superconducting single-photon detectors (SSPDs) have become the unquestioned leader in high performance single-photon detection, counting, and imaging. The detection mechanism of SSPDs is based on photon-induced hotspot formation and, subsequent, generation of a voltage transient across, typically, a superconducting nanostripe meander. The SSPDs operate at cryogenic temperatures, in the 2-5 K range, and are currently the best performance single-photon counters, signicantly outperforming in the telecommunication wavelength any competing commercial and research devices, including semiconducting avalanche photodiodes and other superconducting photon detectors. This talk presents a historical overview of the physics and operation of SSPDs, as well as their practical implementations in areas ranging from quantum communication and cryptography, through medical optical tomography and LIDAR, to noninvasive testing of VLSI integrated circuits. We also comment on possible future directions of the superconducting single-photon detector technology.