Can superconductive digital systems compete with semiconductor systems?

The authors review the current status of silicon microprocessors and memories, and briefly contrast this with the current status of superconducting processors and memories. Possible applications for conventional Josephson computers are mentioned, and the difficulties in supplanting silicon technology by any new technology are discussed. An alternate strategy of hybridizing superconductor and semiconductor circuits is proposed. These hybrid circuits will be able to outperform either technology separately. The hybrid circuits combine the virtues of semiconductor circuits which have high density and excellent manufacturability with the virtues of superconductor circuits which are extremely sensitive in detecting currents and have the capability to drive currents in low impedance lines. The authors examine how hybrid circuits can improve two deficiencies of conventional silicon technology, high power dissipation in interconnection circuits and long memory access times, without requiring the use of many superconductive devices.<>