Josephson phase qubit circuit for the evaluation of advanced tunnel barrier materials

作者：Jeffrey S. Kline, Haohua Wang, Seongshik Oh, John M. Martinis, David P. Pappas · 发表于：Superconductor Science and Technology · 年份：2008 · DOI：10.1088/0953-2048/22/1/015004 · 被引用次数：32 · 研究领域：Physics of Superconductivity and Magnetism、Quantum and electron transport phenomena、Semiconductor Quantum Structures and Devices

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 2 O 3 advanced crystalline tunnel barriers to AlO x amorphous tunnel barrier qubits.