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arXiv · 1711.10230

Transmission x-ray microscopy at low temperatures - analyzing supercurrents with high spatial resolution

J. Simmendinger·S. Ruoss·C. Stahl·M. Weigand·J. Gräfe·G. Schütz·J. Albrecht
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Abstract

Scanning transmission x-ray microscopy has been used to image electric currents in superconducting films at temperatures down to 20 K. The magnetic stray field of supercurrents in a thin YBaCuO film is mapped into a soft-magnetic coating of permalloy. The so created local magnetization of the ferromagnetic film can be detected by dichroic absorption of polarized x-rays. To enable high-quality measurements in transmission geometry the whole heterostructure of ferromagnet, superconductor and single-crystalline substrate has been thinned to an overall thickness of less than 1 micron. With this novel technique local supercurrents can be analyzed in a wide range of temperatures and magnetic fields. A magnetic resolution of less than 100nm together with simultaneously obtained nanostructural data allow the correlation of local supercurrents with the micro- and nanostructure of the superconducting film.

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J. Simmendinger, S. Ruoss, C. Stahl, M. Weigand, J. Gräfe, G. Schütz, J. Albrecht. 2017-11-28. Transmission x-ray microscopy at low temperatures - analyzing supercurrents with high spatial resolution. https://doi.org/10.1103/physrevb.97.134515

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