Self-shunted Al/AlOx/Al Josephson junctions

Self-shunted aluminum Josephson junctions with high-transparency barriers were fabricated using the shadow-evaporation technique and measured at low temperatures, T ≈ 25 mK. Due to high junction transparency, the IV -characteristics were found to be of only small hysteresis with retrapping-to-switching current ratio of up to 80 %. The observed critical currents were close to the Ambegaokar-Baratoff values (up to 80 − 100 %). Good barrier quality was confirmed by the low subgap leakage currents in the quasiparticle branches, which makes the self-shunted Al junctions promising for application in integrated RSFQ-qubit circuitry.