Title :
Optimized technology for freely positionable Josephson junctions in YBa/sub 2/Cu/sub 3/O/sub 7-x/ fabricated by local ion damaging
Author :
Hollkott, J. ; Jaekel, C. ; Spangenberg, B. ; Kurz, H. ; Kahlmann, F.
Author_Institution :
Inst. fur Halbleitertech., Aachen, Germany
fDate :
3/1/1999 12:00:00 AM
Abstract :
Freely positionable Josephson junctions in high-temperature superconductor thin films are fabricated by a combination of photo- and electron-beam lithography. In selected regions of YBCO thin films point defects are induced by oxygen implantation. These weak links exhibit resistively shunted junction (RSJ)-like voltage-current characteristics close to the junction transition-temperature. Below this temperature, a transition from RSJ to flux-flow behavior is observed. Fraunhofer patterns appear in magnetic modulation measurements at different temperatures. The temperature dependence of the critical current reveals superconductor/normal conductor/superconductor (SNS) features. The dependence of Shapiro steps on microwave power demonstrates Josephson contributions over the entire temperature range.
Keywords :
Josephson effect; barium compounds; electron beam lithography; high-temperature superconductors; ion implantation; photolithography; superconducting thin films; yttrium compounds; Fraunhofer pattern; Josephson junction; Shapiro step; YBa/sub 2/Cu/sub 3/O/sub 7-x/; YBa/sub 2/Cu/sub 3/O/sub 7/; critical current; current-voltage characteristics; electron beam lithography; fabrication technology; flux flow; high temperature superconductor thin film; local ion damaging; magnetic modulation; microwave irradiation; oxygen implantation; photolithography; point defect; resistively shunted junction; superconductor/normal conductor/superconductor junction; transition temperature; weak link; High temperature superconductors; Josephson junctions; Lithography; Superconducting devices; Superconducting microwave devices; Superconducting thin films; Temperature dependence; Temperature measurement; Voltage; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
