All-NbN DC-SQUID Magnetometer Based on NbN/AlN/NbN Josephson Junctions

被引：1

作者：

Liu, Quansheng ^{[1
]}

Wang, Huiwu ^{[2
]}

Zhang, Qiyu ^{[3
]}

Ren, Jie ^{[1
,2
]}

Peng, Wei ^{[1
,2
]}

Wang, Zhen ^{[1
,2
]}

机构：

[1] Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai,200050, China

[2] Chinese Academy of Science, Center for Excellence in Superconducting Electronics, Shanghai,200050, China

[3] University of Chinese Academy of Sciences, Beijing,100049, China

来源：

IEEE Transactions on Applied Superconductivity | 2017年 / 27卷 / 04期

关键词：

Josephson junction devices - Single crystals - Shellfish - Magnetic fields - Aluminum compounds - Magnesia - Quantum optics - Temperature - Molluscs;

D O I：

10.1109/TASC.2016.2631433

中图分类号：

学科分类号：

摘要：

We have developed an all-NbN-integrated dc SQUID magnetometer for future applications in the higher operating temperature by taking advantage of NbN films' higher critical temperature about 16 K. Our NbN dc SQUID magnetometer is fabricated on a single crystal MgO (100) substrate, consisting of epitaxial NbN/AlN/NbN Josephson junctions, Ti/Pd shunt resistors, and a top 400-nm-Thick NbN wiring layer. The critical current, inductance, and shunt resistance of NbN SQUID are set at 20 μA, 240 pH, and 1 Ω, respectively. We measured the current-voltage characteristics, voltage-flux characteristics and flux noise of the NbN SQUID magnetometer in a superconductive niobium shield at 4.2 K. In a flux locked loop operation mode, the NbN SQUID magnetometer exhibits excellent performances with a flux noise level of 6 μΦ0 /√Hz in the white region. The corner frequency is only 10 Hz. Based on the calibrated magnetic field sensitivity of 1.7 nT/Φ0 at magnetically shielded room, the magnetic field resolution of 10 fT/√Hz is achieved. © 2002-2011 IEEE.

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