Modulation depth of series SQUIDs modified by Josephson junction area

The superconducting quantum interference device（SQUID） amplifier is widely used in the field of weak signal detection for its low input impedance, low noise, and low power consumption. In this paper, the SQUIDs with identical junctions and the series SQUIDs with different junctions were successfully...

Full description

Saved in:
Bibliographic Details
Published in:Chinese physics B 2017-08, Vol.26 (9), p.496-501
Main Author: 刘杰 高鹤 李刚 李正伟 Kamal Ahmada 张颖珊 刘建设 陈炜
Format: Article
Language:English
Subjects:
Josephson结
SQUID器件
原子力显微镜
微弱信号检测
改性
调制深度
超导量子干涉器件
鱿鱼
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The superconducting quantum interference device（SQUID） amplifier is widely used in the field of weak signal detection for its low input impedance, low noise, and low power consumption. In this paper, the SQUIDs with identical junctions and the series SQUIDs with different junctions were successfully fabricated. The Nb/Al-AlOx/Nb trilayer and input Nb coils were prepared by asputtering equipment. The SQUID devices were prepared by a sputtering and the lift-off method.Investigations by AFM, OM and SEM revealed the morphology and roughness of the Nb films and Nb/Al-AlOx/Nb trilayer.In addition, the current–voltage characteristics of the SQUID devices with identical junction and different junction areas were measured at 2.5 K in the He^3 refrigerator. The results show that the SQUID modulation depth is obviously affected by the junction area. The modulation depth obviously increases with the increase of the junction area in a certain range. It is found that the series SQUID with identical junction area has a transimpedance gain of 58 Ω approximately.
ISSN:1674-1056
2058-3834
DOI:10.1088/1674-1056/26/9/098501