Advanced HTS Superconductor-Normal-Superconductor Devices

Superconductors can be used in integrated circuits based on Josephson junction devices that bring performance advantages in speed and low power dissipation. The discovery of high-temperature superconductors (HTS) has created the opportunity for such circuits to function at unprecedented high temperatures. It is likely that very high speed superconducting integrated circuits operating at 30 to 77 K and based on yttrium-barium-copper-oxide (YBCO) will use Josephson junctions of the SNS type, where N is a metallic oxide which is epitaxial and chemically compatible with YBCO. In this project, we will make and study such metallic oxides, first as thin films to determine their physical properties, then as the N layer of SNS junctions both in the form of trilayer sandwich devices and as so-called edge junctions. We will thus be able to choose the optimum material and device structure to be used in HTS digital circuits.