Nanocryotron ripple counter integrated with a superconducting nanowire single-photon detector for megapixel arrays

Scaling up cryogenic systems, like arrays of superconducting nanowire single-photon detectors (SNSPDs), requires developing cryogenic coprocessors to minimize the number of cables exiting the cryostat. This work addresses this challenge by demonstrating the ability to read out, process, encode, and store data from SNSPDs using integrated nanowire electronics. The authors design a digital counter based on nanocryotrons---three-terminal nanowire devices---to perform signal processing and digitization at low temperatures. These results suggest that nanowire coprocessors could be developed, which would benefit the application of SNSPD arrays and other superconducting platforms.