Possible three-terminal device with YBCO angle grain boundary

The DC and AC Josephson effects were observed in YBa₂Cu ₃O_7-a (YBCO) bridges with metal-organic chemical vapor deposited (MOCVD) thin films on (100)MgO substrates. In TEM observations and X-ray analysis, the angle grain boundaries (AGBs) in these films were observed. Josephson junction resulting from the AGBs showed the semiconducting barrier junction property dominantly, and the AGBs consisted of YBCO with oxygen deficiency. Based on these results, the authors propose a three-terminal device with the Josephson junction. The Josephson junction can be prepared by depositing an epitaxial YBCO thin film with one AGB on a bicrystal (100)SrTiO₃ or (100)Si substrate, and the insulated gate for the application of electric field to the AGB is formed over the junction. The supercurrent in the Josephson junction is controlled by the electric field effect of the semiconducting AGB in the junction