Improvement of integrated circuits and speed of computers concerned with their miniaturization demands considerable financial and mental power today. At the moment the innovation is limited by theoretical possibilities. It seems that new results can be reached by Josephson effects. The Josephson junctions consist of three layer instruments based on quantum tunnelling effect. The digital circuits based on the Josephson junction are developed in new ways. The first flip-flop led to ADC-DAC integrated circuits and further to microprocessors. Solving difficulties, the very high speed quantum computer based on Josephson junctions will be constructed in the first decade of this century.Improvement of integrated circuits and speed of computers concerned with their miniaturization demands considerable financial and mental power today. At the moment the innovation is limited by theoretical possibilities. It seems that new results can be reached by Josephson effects. The Josephson junctions consist of three layer instruments based on quantum tunnelling effect. The digital circuits based on the Josephson junction are developed in new ways. The first flip-flop led to ADC-DAC integrated circuits and further to microprocessors. Solving difficulties, the very high speed quantum computer based on Josephson junctions will be constructed in the first decade of this century.

Pollack PeriodicaDec 1, 20070 citations

Development of integrated digital circuits with Josephson junctions

W. Jutzi

Apr 1, 19840 citations

20 ${\hbox{kA/cm}}^{2}$ Process Development for Superconducting Integrated Circuits With 80 GHz Clock Frequency20 ${\hbox{kA/cm}}^{2}$ Process Development for Superconducting Integrated Circuits With 80 GHz Clock Frequency

Sergey K. Tolpygo, Daniel T. Yohannes, R. T. Hunt +4 more

Results of the development of an advanced fabrication process for superconductor integrated circuits (ICs) with 20 kA/cm2Nb/AlOx/Nb Josephson junctions is presented. The process has 4 niobium superconducting layers, one MoNxresistor layer with 4.0 Ohm per square sheet resistance for the junction shunting and circuit biasing, and employs circular Josephson junctions with the minimum diameter of 1 mum; total 11 photolithography levels. The goal of this process development is the demonstration of the feasibility of 80 GHz clock speeds in superconducting ICs for digital signal processing (DSP) and high performance computing. Basic components of rapid single flux quantum (RSFQ) logic such as DC/SFQ, SFQ/DC converters, Josephson transmission lines (JTLs), and simple digital circuits such as T-flip-flops and 4-bit digital counters have been fabricated and tested. The T-flip-flops were shown to operate up to 400 GHz with the widest margin of operation of plusmn13% at 325 GHz. Digital testing results on the 4-bit counters as well as the junctions, resistors, and other process parameters are also presented. Prospects for yet higher speeds and very large scale integration are discussed.Results of the development of an advanced fabrication process for superconductor integrated circuits (ICs) with 20 kA/cm2Nb/AlOx/Nb Josephson junctions is presented. The process has 4 niobium superconducting layers, one MoNxresistor layer with 4.0 Ohm per square sheet resistance for the junction shunting and circuit biasing, and employs circular Josephson junctions with the minimum diameter of 1 mum; total 11 photolithography levels. The goal of this process development is the demonstration of the feasibility of 80 GHz clock speeds in superconducting ICs for digital signal processing (DSP) and high performance computing. Basic components of rapid single flux quantum (RSFQ) logic such as DC/SFQ, SFQ/DC converters, Josephson transmission lines (JTLs), and simple digital circuits such as T-flip-flops and 4-bit digital counters have been fabricated and tested. The T-flip-flops were shown to operate up to 400 GHz with the widest margin of operation of plusmn13% at 325 GHz. Digital testing results on the 4-bit counters as well as the junctions, resistors, and other process parameters are also presented. Prospects for yet higher speeds and very large scale integration are discussed.

IEEE Transactions on Applied SuperconductivityJun 1, 200772 citations

Applications of Josephson Electronics in Digital Systems

John X. Przybysz

Springer eBooksJan 1, 20001 citation

{\hbox{kA/cm}}^{2}

Process Development for Superconducting Integrated Circuits With 80 GHz Clock Frequency