- You are here: Home > Are all HTS Josephson junctions the same?
You are here
Are all HTS Josephson junctions the same?
Josephson junctions are the basis of all active superconducting electronics. Since the discovery of high temperature superconducting (HTS) materials and YBCO, in particular, a number of different methods of junction fabrication have been devised on a range of different substrates; grain boundary step-edges, bi-epitaxial, bi-crystal and ramp junctions are common examples. The properties of these junctions vary with differences in the range of critical currents and normal resistance that are achievable, their response to magnetic fields and the amount of s-or d-wave phase shifting across the junction. Superconducting electronic applications are broad ranging including SQUIDs for magnetometry, gradiometry, macroscopic quantum state formation for quantum computer qubits, and microwave and terahertz resonators and detectors. However the requirements of the Josephson junction for each of these applications are quite different. This paper will review four different Josephson junction types and what their properties are by considering the impact of the junction morphology and the substrate material on their demonstrated characteristics. We will report on various devices fabricated at CSIRO and use some data from the literature. We will show that these different junctions have different s- and d-wave contributions as well as other properties that make different junctions more appropriate for each specific application in superconducting electronics.