YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-</sub> dc SQUID array for multichannel magnetometry and multichannel flip-chip current sensors
J Ramos; V Zakosarenko; R IJsselsteijn; R Stolz; V Schultze; A Chwala; H E Hoenig; H-G Meyer; J Ramos; Institute for Physical High Technology, Department of Cryoelectronics, PO Box 100239, D-07702 Jena, Germany; V Zakosarenko; Institute for Physical High Technology, Department of Cryoelectronics, PO Box 100239, D-07702 Jena, Germany; R IJsselsteijn; Institute for Physical High Technology, Department of Cryoelectronics, PO Box 100239, D-07702 Jena, Germany; R Stolz; Institute for Physical High Technology, Department of Cryoelectronics, PO Box 100239, D-07702 Jena, Germany; V Schultze; Institute for Physical High Technology, Department of Cryoelectronics, PO Box 100239, D-07702 Jena, Germany; A Chwala; Institute for Physical High Technology, Department of Cryoelectronics, PO Box 100239, D-07702 Jena, Germany; H E Hoenig; Institute for Physical High Technology, Department of Cryoelectronics, PO Box 100239, D-07702 Jena, Germany; H-G Meyer; Institute for Physical High Technology, Department of Cryoelectronics, PO Box 100239, D-07702 Jena, Germany
Журнал:
Superconductor Science and Technology
Дата:
1999-09-01
Аннотация:
We have prepared arrays of single-layer washer-type dc superconducting quantum interference devices (SQUIDs) on 10 mm × 10 mm bicrystal substrates. Each SQUID in the array is equipped with its own modulation loop, which makes a separate operation of them possible. Arrays containing nine or 11 dc SQUIDs have been tested and the crosstalk between neighbouring channels has been found to be 5%. The field sensitivity of the SQUIDs is 85 nT <sub>0</sub><sup>-1</sup> and 105 nT <sub>0</sub><sup>-1</sup> for the nine- and 11-device array, respectively. The equivalent flux noise is typically 20 <sub>0</sub> Hz<sup>-1/2</sup> down to 1 Hz with ac bias reversal. A field resolution of less than 2.1 pT Hz<sup>-1/2</sup> has been obtained for at least eight channels on a chip. By using multiturn YBa<sup>2</sup>Cu<sub>3</sub>O<sub>7-</sub> input coils and mounting them in a flip-chip configuration together with the single-layer dc SQUIDs we have been able to build three-channel current sensors. The current sensitivity equals 3-3.5 A <sub>0</sub><sup>-1</sup> depending on the alignment of the flip-chip configuration. The current resolution of the devices is < 70 pA Hz<sup>-1/2</sup>. We show the possibility of building sensitive magnetometers by connecting the input coil of these current sensors to a normal-conducting pickup antenna.
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