A Grain Boundary Josephson Junction that Supported Many Careers and Led to Applications with Impact

CSIRO is the Australian national science agency and has been working in superconducting electronics since the 1970s. With the discovery of high-temperature superconductivity in 1986, CSIRO supported a team of researchers to work on YBa 2 Cu 3 O 7-x (YBCO) step-edge Josephson junctions. This junction technology is the basis of many different HTS devices and sensors. The CSIRO team used these devices in a range of systems for many different applications. This paper briefly reports on the development of the HTS YBCO step-edge junction formed on MgO. It also presents several systems developed with a focus on the most successful commercial system so far called LANDTEM™. This system is used for mineral exploration and has been successful in supporting the delineation and discovery of many billions of dollars of ore bodies. Over a 30-year period, the Josephson junction has been the basis of research for the CSIRO superconductivity team and provided all the team members with rich and fulfilling careers.