Low-frequency excess noise in YBa[sub 2]Cu[sub 3]O[sub 7[minus][ital x]] dc superconducting quantum interference devices cooled in static magnetic fields

Journal Article · Mon Jun 20 00:00:00 EDT 1994 · Applied Physics Letters; (United States)

DOI:https://doi.org/10.1063/1.111251· OSTI ID:7114771

Miklich, A H; Koelle, D; Shaw, T J; Ludwig, F; Nemeth, D T; Dantsker, E; Clarke, J ^[1]; McN Alford, N; Button, T W ^[2]; Colclough, M S ^[3]

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1. Department of Physics, University of California, Berkeley, California 94720 (United States) Materials Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)
2. ICI Superconductors, Tioxide Specialties Ltd., West Site, Haverton Hill Road, Billingham, Cleveland, TS23 1PS (United Kingdom)
3. Conductus, Inc., 969 W. Maude Avenue, Sunnyvale, California 94086 (United States)

We have investigated the performance of YBa[sub 2]Cu[sub 3]O[sub 7[minus][ital x]] dc superconducting quantum interference devices (SQUIDs) cooled in static magnetic fields, [ital B][sub 0], of 0.01--1 mT. For fields less than the earth's ambient field, about 0.05 mT, the white noise of the devices at 77 K is not materially affected. However, at a frequency [ital f] of 1 Hz the spectral density of the 1/[ital f] noise, [ital S][sub [Phi]] (1 Hz), at 0.05 mT increases by an order of magnitude over that for zero field. Furthermore, [ital S][sub [Phi]] (1 Hz) scales approximately linearly with [ital B][sub 0], suggesting strongly that the noise originates in the motion of vortices in the YBCO film. This increase in noise is likely to be an issue for SQUIDs operated in the earth's field.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 7114771
• Journal Information: Applied Physics Letters; (United States), Vol. 64:25; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
HIGH-TC SUPERCONDUCTORS
NOISE
SQUID DEVICES
BARIUM OXIDES
COPPER OXIDES
FREQUENCY DEPENDENCE
QUATERNARY COMPOUNDS
SUPERCONDUCTING FILMS
VORTEX FLOW
YTTRIUM OXIDES
ALKALINE EARTH METAL COMPOUNDS
AMINES
AMMONIUM COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
ELECTRONIC EQUIPMENT
EQUIPMENT
FILMS
FLUID FLOW
FLUXMETERS
MEASURING INSTRUMENTS
MICROWAVE EQUIPMENT
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SUPERCONDUCTING DEVICES
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360207* - Ceramics
Cermets
& Refractories- Superconducting Properties- (1992-)