Work

Enhanced superconducting properties of Bi$$_2$$Sr$$_2$$CaCu$$_2$$O$$_{8+x}$$ films with sub-50-nm thickness

Year: 2025

Type: article

Abstract: Few-unit cell thick Bi[Formula: see text]Sr[Formula: see text]CaCu[Formula: see text]O[Formula: see text] (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.

Source: Scientific Reports

DOI: 10.1038/s41598-025-95932-9

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

Institutions: University of Vienna, Johannes Kepler University of Linz

Language: English

Topic: Physics of Superconductivity and Magnetism

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,690

Funder: Austrian Science Fund