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Low-frequency flux noise and visualization of vortices in a YBa2Cu3O7 dc SQUID washer with an integrated input coil

R. Straub·S. Keil·R. Kleiner·D. Koelle
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Abstract

We used low-temperature scanning electron microscopy (LTSEM) for imaging quantized magnetic flux (vortices) in direct current (dc) superconducting quantum interference devices (SQUIDs) with approximately 1 micron spatial resolution at temperature T=77 K in a controllable magnetic field up to 20 microTesla. We demonstrate that LTSEM allows to image the spatial distribution of vortices in a YBa2Cu3O7/SrTiO3/YBa2Cu3O7 multilayer thin-film structure consisting of a dc SQUID washer with an integrated input coil on top. Simultaneously, we are able to measure the low-frequency noise of the sample under test, which allows to correlate the spatial distribution of vortices with low-frequency noise in the SQUID.

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R. Straub, S. Keil, R. Kleiner, D. Koelle. 2001-04-20. Low-frequency flux noise and visualization of vortices in a YBa2Cu3O7 dc SQUID washer with an integrated input coil. https://doi.org/10.1063/1.1378048

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