Low 1/ f noise single-layer YBa sub 2 Cu sub 3 O sub x dc SQUID at 77 K

Journal Article · Mon Jun 15 00:00:00 EDT 1992 · Applied Physics Letters; (United States)

DOI:https://doi.org/10.1063/1.106752· OSTI ID:7182581

Friedl, G; Vildic, M; Roas, B; Uhl, D; Boemmel, F; Roemheld, M; Hillenbrand, B; Stritzker, B; Daalmans, G ^[1]

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1. SIEMENS AG, Research Laboratories, 8520 Erlangen (Germany)

Autonomous single-layer dc superconducting quantum interference devices (SQUIDs) have been prepared from epitaxial, laser-deposited YBa{sub 2}Cu{sub 3}O{sub {ital x}} films on step edge SrTiO{sub 3} and LaAlO{sub 3} substrates. For device patterning, a SiO{sub {ital x}} inhibit technique as well as conventional ethylenediaminetetraacetic wet etch was used. The Josephson junctions are of grain boundary type. Their widths are 5 {mu}m. The SQUID hole is a square of about 5 {mu}m; the SQUID inductance is estimated to be about 20 pH. We obtained a very regular, nonhysteretic flux to voltage modulation over more than 100 flux quanta ({Phi}{sub 0}). The maximum voltage signal is of the order of 15 {mu}V peak to peak and the maximum transfer function {ital dV}/{ital d}{Phi} at the appropriate flux bias is 50 {mu}V/{Phi}{sub 0} at 77 K. The best value of the equivalent flux noise as measured in the flux locked loop mode is 1.4{times}10{sup {minus}5} {Phi}{sub 0}/Hz{sup 1/2} at 1 Hz and 1{times}10{sup {minus}5} {Phi}{sub 0}/Hz{sup 1/2} in the white noise region for {ital f}{gt}5 Hz. This results in an energy resolution {epsilon}{sub {ital n},{ital w}}({ital f}{gt}5 {ital Hz})=1{times}10{sup {minus}29} {ital J}/{ital Hz} {ital in} {ital the} {ital white} {ital noise} {ital region} {ital and} 2{times}10{sup {minus}29} {ital J}/{ital Hz} {ital at} 1 {ital Hz}.

• OSTI ID: 7182581
• Journal Information: Applied Physics Letters; (United States), Vol. 60:24; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BARIUM OXIDES
SQUID DEVICES
COPPER OXIDES
HIGH-TC SUPERCONDUCTORS
YTTRIUM OXIDES
EPITAXY
ETCHING
GRAIN BOUNDARIES
JOSEPHSON JUNCTIONS
NOISE
PERFORMANCE
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
CRYSTAL STRUCTURE
ELECTRONIC EQUIPMENT
EQUIPMENT
FLUXMETERS
JUNCTIONS
MEASURING INSTRUMENTS
MICROSTRUCTURE
MICROWAVE EQUIPMENT
OXIDES
OXYGEN COMPOUNDS
SUPERCONDUCTING DEVICES
SUPERCONDUCTING JUNCTIONS
SUPERCONDUCTORS
SURFACE FINISHING
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
665412* - Superconducting Devices- (1992-)