A 4 b Josephson data processor chip

The authors describe a 4-bit Josephson data processor chip featuring on-chip control and data paths and near-GHz capability. It is a closed, stand-alone chip comprising a 4-bit data path and a control path and is aimed at high-speed digital signal processing. The die is 0.5 mm square, including pads, is fabricated using 2.5- mu m-rule Nb/AlO/sub x//Nb technology, and consists of 8454 Josephson junctions and 9027 resistors. The cross-shaped junction structure realizes critical current scattering of +or-6%, and a junction characteristic voltage V/sub m/ of 50 mV. A block diagram of the Josephson data processor is shown.<
>