  Integration with conventional electronics offers a straightforward and
economical approach to upgrading existing superconducting technologies, such as
scaling up superconducting detectors into large arrays and combining single
flux quantum (SFQ) digital circuits with semiconductor logic and memories.
However, direct output signals from superconducting devices (e.g., Josephson
junctions) are usually not compatible with the input requirements of
conventional devices (e.g., transistors). Here, we demonstrate the use of a
single three-terminal superconducting-nanowire device, called the nanocryotron
(nTron), as a digital comparator to combine SFQ circuits with mature
semiconductor circuits such as complementary metal oxide semiconductor (CMOS)
circuits. Since SFQ circuits can digitize output signals from general
superconducting devices and CMOS circuits can interface existing
CMOS-compatible electronics, our results demonstrate the feasibility of a
general architecture that uses an nTron as an interface to realize a
super-hybrid system consisting of superconducting detectors, superconducting
quantum electronics, CMOS logic and memories, and other conventional
electronics.
