Josephson junctions and superconducting field effect transistors based on epitaxial Bi2Sr2Can-1CunO2(n+2) thin films

Abstract Josephson junctions based on thin films of the Bi 2 Sr 2 Ca 2 Cu 3 O 10+ δ compound show I c R n products compatible with YBa 2 Cu 3 O 7− δ samples. Using quasiparticle tunneling experiments we found evidence for a superconductor–insulator–superconductor tunneling process via localized states in the barrier. The Bi 2 Sr 2 CaCu 2 O 8+ δ compound is investigated regarding possible applications in superconducting field effect devices. We present thin films of four unit cells thickness that are superconducting at 58 K. An inverted metal–insulator–superconductor structure was prepared. From the modulation of the normal state resistance we estimate a carrier density of 7×10 19 cm −3 for a superconducting sample. The shift of the transition temperature was 1 K/V. The modulation of the I – V characteristics was demonstrated.