Investigation of Material Effects With Micro-Sized SQUID Sensors

被引：7

作者：

Bechstein, S. ^{[1
]}

Kirste, A. ^{[1
]}

Drung, D. ^{[1
]}

Regin, M. ^{[1
]}

Kazakova, O. ^{[2
]}

Gallop, J. ^{[2
]}

Hao, L. ^{[2
]}

Cox, D. ^{[2
]}

Schurig, T. ^{[1
]}

机构：

[1] PTB, D-10587 Berlin, Germany

[2] Natl Phys Lab, Teddington TW11 0LW, Middx, England

来源：

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY | 2013年 / 23卷 / 03期

关键词：

Linearity; magnetic susceptibility; particle measurements; SQUIDs; superconducting coils; superconducting device noise; superconducting integrated circuits;

D O I：

10.1109/TASC.2012.2235505

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

Micro-sized SQUID sensors have been designed and fabricated in conventional wNb/AlOx/Nb junction technology. Two types are presented here: a microSQUID gradiometer with two small loops, each with a diameter of 3 mu m, and an integrated susceptometer having 30 mu m or 60 mu m circular loops and on-chip field coils. Both sensor types have been read out by a SQUID array, acting as a low-noise preamplifier. The microSQUIDs were operated in a temperature range of 4.2 K to 7 K, whereas the susceptometers are rather intended for operation below 4.2 K. Important SQUID parameters such as flux noise, maximum operation field, and nonlinearity were measured at different temperatures. The best white flux noise level achieved with a microSQUID was 135 n Phi(0)/Hz(1/2) at 4.2 K. Micro-sized magnetic beads were investigated with microSQUIDs, whereas susceptometers were used to measure the susceptibility of thin wires up to 100 kHz.

引用

页数：4