Very fast electronics: Following the semiconductor roadmap or searching new ways with superconducting electronics?

Prof.dr. Horst Rogalla, Low Temperature Division, University of Twente, the Netherlands

Data processing via semiconductor electronics followed for many years the semiconductor roadmap regularly published by the semiconductor industry: a doubling in integration density every 2 years and associated an increase in data processing speed by a factor of 10 every 5 years. This combination will come to an end: with further increase in the integration density the data processing speed will decrease and thermal problems will inhibit higher integration densities for fast data processing. Many solutions to this problem have been suggested and quite some have been tested. Superconducting Electronics plays in this respect a special role: in recent years the unique features of superconductors have systematically been investigated for possible applications in data processing, either in combination with semiconductors or in a fully superconducting environments. Not only is the data transfer on superconducting transmission lines nearly lossless and dispersion free up to THz frequencies, but also are there switching elements available (Josephson Junctions), which show switching times of about a psec at switching energy-delay products of less than 10-30 Js, orders of magnitude less than for semiconductor devices.
In this talk I will report on the ongoing basic research for developing new types of Josephson Junctions as switching elements and for the improvement of the currently available technology, such as wave-symmetry phase shifters and interface control on a sub-nanometer scale. In a second part I will report about applications of superconducting electronics in the data processing technology and first developments towards industrial applications.