Competence Center for Micro- and Nanotechnologies

Rapid single flux quantum (RSFQ) electronics is based on the Josephson junction as active switching element. In standard RSFQ circuits its switching energy is much lower than the static power consumption caused by the resistive current distribution network. Due to this thermal heating of the chip, the maximum number of junctions on a single chip is limited to about 1 million. The frequency-dependent contribution to power dissipation from junction switchings is only about 2 percent of the static one. This fact limits the direct construction of VLSI systems for high-performance computing as well as small-scale circuit applications in the vicinity of ultra-sensitive detectors or even quantum circuits. We present an assessment of different approaches for reducing the static power consumption by investigating the potential of inductive bias distribution networks as well as reduced critical currents. We demonstrate the operation stability of simple digital circuits with 5 times smaller critical currents at 4.2 Kelvin and discuss possible applications. The combination of new design approaches can provide digital superconductive circuits in which static and dynamic power consumption have a similar amount.