Enhanced superconducting properties of Bi₂Sr₂CaCu₂O_8+x films with sub-50-nm thickness

Author(s)

Bernd Aichner, Sandra Keppert, Johannes D. Pedarnig, Wolfgang Lang

Abstract

Few-unit cell thick Bi₂Sr₂CaCu₂O_8+x (Bi-2212) layers have recently attracted much interest due
to their extreme anisotropy and two-dimensional superconductivity, although they are typically
susceptible to ambient conditions. In this study, we report on thin films approximately 13 unit cells thick that are stable in air, exhibit high anisotropy, and demonstrate extraordinarily high critical currents. By examining the superconducting transition under magnetic fields applied in both out-of-plane and in-plane orientations, we estimate key parameters such as pinning potentials, coherence lengths, London penetration depth, anisotropy factor, and the Ginzburg–Landau parameter. The volume pinning force is better described by a model incorporating an exponential decay term attributed to pronounced thermally-assisted flux flow. The Hall effect in the Bi-2212 films exhibits an extensive anomaly with a double sign change that may challenge existing theoretical explanations for this poorly understood phenomenon in copper-oxide superconductors.

Organisation(s)

Nanomagnetism and Magnonics, Electronic Properties of Materials

External organisation(s)

Johannes Kepler Universität Linz

Journal

Scientific Reports

Volume

15

No. of pages

12

ISSN

2045-2322

DOI

https://doi.org/10.1038/s41598-025-95932-9

Publication date

04-2025

Peer reviewed

Yes

Austrian Fields of Science 2012

103033 Superconductivity, 103009 Solid state physics, 103042 Electron microscopy

Keywords

Portal url

https://ucrisportal.univie.ac.at/en/publications/ea50bcb0-8327-4e82-80c4-cb940289282a