Patent ID: 7336981

Claim:
A superconductor insulator superconductor step edge Josephson junction, comprising: a single layer of a copper oxide superconductor deposited onto a single crystal substrate of the formula Sr 2 YbSbO 6 ; said single crystal substrate being heated for at least 20 hours at between 1400° C. and 1600° C.; said single crystal substrate having an ordered perovskite pseudo-cubic tetragonal crystalline structure; said single crystal substrate having a low dielectric constant between 4.1 and 16.3; said single crystal substrate having a low dielectric loss of less than 1.0×10 −3 without a phase transition; said single crystal substrate having a density GM/CC of 5.87; said single layer of the copper oxide superconductor being patterned; a second layer of Sr 2 YbSbO 6 deposited onto said single layer of the copper oxide superconductor; said formula including an Sb 5+ constituent atom with a polarizability of about 1.2 Å 3 ; and a second layer of the copper oxide superconductor deposited and patterned on said second layer of Sr 2 YbSbO 6 .