A 60-GHz NbN single-flux quantum counter circuit
Abstract
A Josephson binary counter using single-flux quanta transitions of DC SQUIDs has been fabricated using an eight-level NbN-based process. High-speed binary division has been demonstrated at 4.2 K, with single-cell counting observed at 60 GHz using the Josephson voltage-to-frequency relationship. Count rate was primarily limited by conservative process and design rules. The counter was designed for operation at 4.2 K. At 8-10 K, the betalL of the SQUIDs would not allow operation, though the junction characteristics were good.
- Publication:
-
IEEE Journal of Solid-State Circuits
- Pub Date:
- June 1991
- DOI:
- 10.1109/4.78279
- Bibcode:
- 1991IJSSC..26..884S
- Keywords:
-
- Josephson Junctions;
- Niobium Compounds;
- Nitrides;
- Quantum Counters;
- Squid (Detectors);
- Flip-Flops;
- Temperature Dependence;
- Electronics and Electrical Engineering