Development of 0.5-V Josephson junction array devices for quantum voltage standards

• 来源期刊: 中国物理B（英文版）
• 关键词: Josephson voltage standards Josephson junction superconducting-normal metal–superconducting (SNS) junction quantum device
• 年，卷（期）: 2019,（6）
• 页码范围: 515-520
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-1056/28/6/068501

摘要

The design, fabrication, and the characterization of a 0.5-V Josephson junction array device are presented for the quantum voltage standards in the National Institute of Metrology (NIM) of China. The device consists of four junction arrays, each of which has 12003-stacked Nb/Nbx Si1?x/Nb junctions and an on-chip superconducting microwave circuit which is mainly a power divider enabling each Josephson array being loaded with an equal amount of microwave power. A direct current (dc) quantum voltage of about 0.5 V with a～1-mA current margin of the 1st quantum voltage step is obtained. To further prove the quality of NIM device, a comparison between the NIM device with the National Institute of Standards and Technology (NIST) programmable Josephson voltage standard (PJVS) system device is conducted. The difference of the reproduced 0.5-V quantum voltage between the two devices is about 0.55 nV, which indicates good agreement between the two devices. With the homemade device, we have realized a precise and applicable 0.5-V applicable-level quantum voltage.