A trilayer process for the fabrication of Al phase qubits

作     者：XUE GuangMing YU HaiFeng TIAN Ye DENG Hui LIU WeiYang REN YuFeng YU HongWei ZHENG DongNing ZHAO ShiPing 

作者机构：Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of Sciences 

出 版 物：《Science China(Physics,Mechanics & Astronomy)》 (中国科学：物理学、力学、天文学（英文版）)

年 卷 期：2013年第56卷第12期

页      面：2377-2380页

核心收录：

学科分类：070207[理学-光学] 07[理学] 08[工学] 0803[工学-光学工程] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11104340 and 11104332) the Ministry of Science and Technology of China(Grant Nos.2009CB929102 and 2011CBA00106) 

主　　题：Josephson junction trilayer process superconducting qubit 

摘      要：Herein we develop an Al/AlOx/Al trilayer process, feasible to fabricate complex circuits with wiring crossovers, for the preparation of A1 junctions and phase qubits. The AlOx layer is obtained by in situ thermal oxidation, which provides high-quality junction tunnel barriers. The A1 junctions show a considerably low leakage current and the Josephson critical current density can be conveniently controlled in the range of a few to above 100 A/cm2, which is favorable in the phase qubit application. Macroscopic quantum tunneling, energy spectrum, energy relaxation time, Rabi oscillation, and Ramsey interference of the A1 phase qubits are measured, demonstrating clearly quantum coherent dynamics with a timescale of 10 ns. Further improvements of the coherent dynamic properties of the device are discussed.