Midgap state-based π-junctions for digital applications
Abstract
Midgap state-based YBa2Cu3O7-x π-junctions have been fabricated by a focused ion-beam system using 45° symmetric [001] tilt SrTiO3 bicrystal substrates. Measurements, performed by inserting the junctions in a superconducting loop (as a double-phase sensitive test), show both an unconventional nonmonotonic temperature dependence of the Josephson current, with a local minimum at a crossover temperature T * and, around T*, a half flux quantum shift in the critical current versus magnetic field modulations, clear signs of a 0-π crossover with temperature. Such results demonstrate that conventional 45° symmetric grain boundary junctions may have potential for applications, from digital circuits to quantum computing.
- Publication:
-
Applied Physics Letters
- Pub Date:
- August 2004
- DOI:
- 10.1063/1.1781744
- Bibcode:
- 2004ApPhL..85.1202T
- Keywords:
-
- 85.25.Dq;
- 74.25.Sv;
- 74.50.+r;
- 74.70.Dd;
- 81.15.Fg;
- Superconducting quantum interference devices;
- Critical currents;
- Tunneling phenomena;
- point contacts weak links Josephson effects;
- Ternary quaternary and multinary compounds;
- Laser deposition