MEASUREMENT OF THE DYNAMIC ERROR RATE OF A HIGH-TEMPERATURE SUPERCONDUCTOR RAPID SINGLE FLUX QUANTUM COMPARATOR

The application of high temperature superconductor (HTS) Josephson jun ctions in digital rapid single flux quantum circuits requires a carefu l study of the influence of thermal noise on the bit error rate (BER). We have determined experimentally, for the first time, the BER of a H TS rapid single flux quantum circuit. A comparator, formed by two Jose phson junctions, was integrated in a Josephson transmission line ring oscillator, allowing us to perform high speed testing of the comparato r at GHz frequencies. For fabrication, focused-electron-beam-irradiate d junctions have been used because of their small parameter spread and excellent alignment possibilities. A BER of less than 10(-11) was obt ained at 39 K. (C) 1998 American Institute of Physics.