Anisotropic, multiband, and strong-coupling superconductivity of the Pb0.64Bi0.36 alloy

Autor(en)

Sylwia Gutowska, Karolina Górnicka, Paweł Wójcik, Tomasz Klimczuk, Bartlomiej Wiendlocha

Abstrakt

This paper presents theoretical and experimental studies on the superconductivity of Pb0.64Bi0.36 alloy, which is a prototype of strongly coupled superconductors and exhibits one of the strongest coupling under ambient pressure among the materials studied so far. The critical temperature, the specific heat in the superconducting state, and the magnetic critical fields are experimentally determined. Deviations from the single-gap s-wave BCS-like behavior are observed. The electronic structure, phonons, and electron-phonon interactions are analyzed in relation to the metallic Pb, explaining why the Pb-Bi alloy exhibits such a large value of the electron-phonon coupling parameter λ≃2. Superconductivity is studied using the isotropic Eliashberg formalism as well as the anisotropic density functional theory for superconductors. We find that while Pb is a two-gap superconductor with well-defined separate superconducting gaps, in the Pb-Bi alloy an overlapped three-gap-like structure is formed with a strong anisotropy. Furthermore, the chemical disorder, inherent to this alloy, leads to strong electron scattering, which is found to reduce the critical temperature.

Organisation(en)

Computergestützte Materialphysik

Externe Organisation(en)

AGH University of Science and Technology, Oak Ridge National Laboratory , Gdańsk University of Technology

Journal

Physical Review B

Band

110

Anzahl der Seiten

22

ISSN

2469-9950

DOI

https://doi.org/10.48550/arXiv.2411.18315

Publikationsdatum

12-2024

Peer-reviewed

Ja

ÖFOS 2012

103033 Supraleitung, 103018 Materialphysik

ASJC Scopus Sachgebiete

Electronic, Optical and Magnetic Materials, Condensed Matter Physics

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/d80c48a5-6cac-4426-a311-6566e76512b5