超导磁通量子比特的性能表征

Characterization of a superconducting flux qubit

采用超导电路实现的量子计算近十几年来发展迅速,目前已经实现了质因数15的分解、高保真度的单和双量子比特等等。为实现量子计算,采用正交剥离自对准工艺,制备了射频超导量子干涉器件(rf-SQUID)结构的超导磁通量子比特芯片。在稀释制冷机mK温度下,对其基本结构参数进行了表征,并通过理论分析、软件仿真验证了测试结果。此外,还分析了测试系统的噪声性能,对可能的噪声源进行了消除。最后,通过量子比特初态的制备,观测到了双势阱能级间的共振隧穿现象。

Last decade quantum computing based on superconducting circuits has a rapid development. It has accomplished the factorization of 15, the high-fidelity single and double qubit operations. To achieve quantum computing, rf-SQUID qubit was fabricated using a self - aligning technology, and a mill - kelvin measurement system was constructed to characterize the rf-SQUID qubit with the using of a dc-SQUID. Based on the system, we characterized its basic parameters and verified by theoreti-cal analysis and software simulation. Furthermore, we eliminated the possible sources of noise and observed resonant tunneling by preparing initial states.