Josephson junction infrared single-photon detector

Josephson junctions are superconducting devices used as high-sensitivity magnetometers and voltage amplifiers as well as the basis of high-performance cryogenic computers and superconducting quantum computers. Although device performance can be degraded by the generation of quasiparticles formed from broken Cooper pairs, this phenomenon also opens opportunities to sensitively detect electromagnetic radiation. We demonstrate single near-infrared photon detection by coupling photons to the localized surface plasmons of a graphene-based Josephson junction. Using the photon-induced switching statistics of the current-biased device, we reveal the critical role of quasiparticles generated by the absorbed photon in the detection mechanism. The photon sensitivity will enable a high-speed, low-power optical interconnect for future superconducting computing architectures.

Automated summary

Josephson junctions serve as high-sensitivity magnetometers and voltage amplifiers, and are crucial for high-performance cryogenic and superconducting quantum computers. Despite the potential degradation in device performance caused by quasiparticle generation, this phenomenon also offers opportunities for detecting electromagnetic radiation with sensitivity.Detection of single photons in near-infrared range has been demonstrated by coupling photons to the localized surface plasmons of a graphene-based Josephson junction, revealing the critical role of quasiparticles in the detection mechanism.