Fabrication of Josephson junctions using heteroepitaxial Bi2(Sr,Ca)3Cu2Ox/Bi2Sr2CuOy/Bi2(Sr,Ca)3Cu2Ox trilayer films

We have fabricated Josephson junctions from c‐axis oriented heteroepitaxial Bi2(Sr,Ca)3Cu2Ox/Bi2Sr2CuOy/Bi2(Sr,Ca)3Cu2Ox trilayer films. The junctions showed resistively shunted junctionlike characteristics up to 30 K. Several junctions showed hysteresis at low temperatures. The highest value of the product of the critical current and the normal state resistance of the junctions was about 0.2 mV. Clear Shapiro steps at the expected voltages were observed in the presence of external microwave irradiation. The height of these steps oscillated to full suppression as a function of the microwave source power. Moreover the periodic magnetic field dependence of the critical current was clearly observed. These results indicated a good uniformity in the Josephson current distribution in these junctions.

[1]  H. Kroger,et al.  Hysteretic Josephson junctions from YBa2Cu3O(7-x)/SrTiO3/Ba(1-x)K(x)BiO3 trilayer films , 1992 .

[2]  G. Virshup,et al.  Engineering of ultrathin barriers in high TC, trilayer Josephson junctions , 1992 .

[3]  G. Virshup,et al.  Hysteretic, high Tc Josephson junctions using heterostructure trilayer films grown by molecular beam epitaxy , 1992 .

[4]  K. Mizushima,et al.  Josephson characteristics in a‐axis oriented YBa2Cu3O7−δ/PrBa2Cu3O7−δ’/YBa2Cu3O7−δ junctions , 1992 .

[5]  T. Yoshitake,et al.  Microstructure of Bi2(Sr,Ca)3Cu2Ox/Bi2Sr2CuOy/ Bi2(Sr,Ca)3Cu2Ox trilayer films fabricated by ion beam sputtering , 1991 .

[6]  K. Setsune,et al.  Fabrication of Bi 2 Sr 2 Ca 1 Cu 2 O 8+δ /Bi 2 Sr 2 Nd 1 Cu 2 O 8+δ /Bi 2 Sr 2 Ca 1 Cu 2 O 8+δ Josephson Junctions , 1991 .

[7]  C. Rogers,et al.  All a‐axis oriented YBa2Cu3O7−y‐PrBa2Cu3O7−z‐YBa2Cu3O7−y Josephson devices operating at 80 K , 1991 .

[8]  A. Schilling,et al.  In-plane London penetration depths near the critical temperature of Tl2Ba2Can−1CunO2n+4 and (Bi, Pb)2Sr2Can−1 CunO2n+4 (n=2,3) , 1991 .

[9]  K. Wasa,et al.  Fabrication of thin-film-type Josephson junctions using a Bi-Sr-Ca-Cu-O /Bi-Sr-Cu-O/Bi-Sr-Ca-Cu-O structure , 1990 .

[10]  T. Yoshitake,et al.  In situ epitaxial growth of Bi2(Sr,Ca)3Cu2Ox films by ion beam sputtering with an atomic oxygen source , 1990 .

[11]  M. S. Hegde,et al.  Fabrication of heteroepitaxial YBa2Cu3O7−x‐PrBa2Cu3O7−x‐YBa2Cu3O7−x Josephson devices grown by laser deposition , 1989 .

[12]  Michael Tinkham,et al.  Self‐heating hotspots in superconducting thin‐film microbridges , 1974 .

[13]  M. Weihnacht.  Influence of Film Thickness on D. C. Josephson Current , 1969 .