Optimized technology for freely positionable Josephson junctions in Yba(2)Cu(3)O(7-x) fabricated by local ion damaging

Freely positionable Josephson junctions in high-temperature superconductor thin films are fabricated by a combination of photo- and electron-beam lith ography, In selected regions of YBCO thin films point defects are induced b y oxygen implantation. These weak links exhibit resistively shunted junctio n (RSJ)-like voltage-current characteristics close to the junction transiti on-temperature. Below this temperature, a transition from RSJ to Bur-flow b ehavior is observed. Fraunhofer patterns appear in magnetic modulation meas urements at different temperatures. The temperature dependence of the criti cal current reveals superconductor/normal conductor/superconductor (SNS) fe atures, The dependence of Shapiro steps on microwave power demonstrates Jos ephson contributions over the entire temperature range.