Patent ID: 7300909
Filing Date: 2007-11-27
Classification: H01L

Abstract:
1. A superconducting circuit comprising: a single flux quantum circuit using a high temperature superconductor; and an interface circuit for said single flux quantum circuit, wherein said single flux quantum circuit is provided with a first Josephson junction, and said interface circuit is provided with a second Josephson junction made from a combination of materials different from those of said first Josephson junction, wherein hysteresis in the current-voltage characteristic of said first Josephson junction is smaller than hysteresis in the current-voltage characteristic of said second Josephson junction, wherein said first Josephson junction comprises: a lower electrode made from La-doped YBaCuO; an upper electrode made from YbBaCuO; and a damage layer formed between the lower electrode and the upper electrode, serving as a barrier, and wherein said second Josephson junction comprises: a lower electrode made from La-doped YBaCuO; an upper electrode made from La-doped YbBaCuO; and a layer made from LaSrAlTaO in addition to a damage layer formed between the lower electrode and the upper electrode, serving as a barrier.