Flux noise from superconducting YBa2Cu3O7−x flux transformers

11 March 1991

journal article
research article
Published by AIP Publishing in Applied Physics Letters

Vol. 58 (10) , 1106-1108
https://doi.org/10.1063/1.104386

Abstract

Using a dc superconducting quantum interference device (SQUID) at 4.2 K, we have measured the magnitude and temperature dependence of the flux noise generated by superconducting flux transformers made from YBa₂Cu₃O_7−x. If the transformer loop is opened, the observed noise decreases by a factor of 10, demonstrating that moving vortices generate noise primarily by altering the screening current, rather than by coupling their magnetic flux directly into the SQUID. Model calculations are given for the various noise contributions, and shown to be reasonable predictions of the observed effects.

Keywords

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