We have found that crystalline Josephson junctions have problems with the control of critical current density that decrease the circuit yield. We present a superconducting quantum bit circuit designed to accommodate a factor of five variation in critical current density from one fabrication run to the next. The new design enables the evaluation of advanced tunnel barrier materials for superconducting quantum bits. Using this circuit design, we compare the performance of Josephson phase qubits fabricated with MgO and Al 2O3 advanced crystalline tunnel barriers to AlO x amorphous tunnel barrier qubits.
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Condensed Matter Physics
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry