Physical and technological limitations of SNS Josephson junctions for large-scale integration low-temperature superconductor circuits
|Seite(n):||96 S., 45 Abb., 7 Tab|
|Zusammenfassung:||The present work investigates the physical and technological limitations of novel SNS Josephson junctions for large-scale integration low-temperature superconductor circuits. Based on intrinsically shunted Nb/HfTi/Nb and Nb/HfTi/Nb/HfTi/Nb junctions a fabrication technology was developed to reproducibly manufacture sub-µm Josephson junctions with junction areas down to A = 0.03 .my.m2. The junctions’ physical properties are investigated with respect to the differential resistance and the dependence of the critical current IC on temperature and an externally applied magnetic field, as well as the influence of microwave irradiation (Shapiro steps).
To realize superconducting digital electronic (SDE) circuits, the capability of thin, sub-µm Nb lines to carry a supercurrent and the respective fringe factor is determined. It is shown that these novel Josephson junction are well suitable for use in large series arrays, which, in metrology, are used for voltage standard circuits. Furthermore the usability of the junctions as active elements in SDE rapid-single-flux-quantum logic circuits implementations is verified.
|Bemerkung:||Physical and technological limitations of SNS Josephson junctions for large-scale integration low-temperature superconductor circuits ; (PTB-Bericht PTB-E-86)|