[Zurück]

S. Manalo, H. Michor, M. Brühwiler, G. Hilscher, B. Batlogg:
"Upper critical field of RbOs₂O₆ analyzed within Eliashberg theory";
Physica C: Superconductivity and its Applications, 460-462 (2007), S. 530 - 531.

Upper critical field of RbOs₂O₆ analyzed within Eliashberg theory

Sherryl Manalo a, Herwig Michor a, Markus Brühwiler b, Gerfried Hilscher a and Bertram Batlogg b

a Institute for Solid State Physics, Vienna University of Technology, Wiedner Hauptstraße 8-10, 1040 Wien, Austria
b Laboratory for Solid State Physics, ETH Zürich, 8093 Zürich, Switzerland

Abstract

The upper critical field H_c2(T) of the β-pyrochlore superconductor RbOs₂O₆ is analyzed within the framework of s-wave Eliashberg theory including anisotropy and scattering effects, yielding a small electron-phonon coupling anisotropy parameter of about <a²> = 0.005, and a Fermi velocity anisotropy parameter <b²> = 0.3-0.35. Agreement between theory and experiment is achieved for these parameters and a model spectral function α²F(ω) consisting of two Einstein peaks and a Debye contribution. A renormalization of the Fermi velocity by an enhancement factor due to electron-electron correlations <υ _F>_ee = 1 is considered in the analysis of the experimental H_c2(T)-data. Comparison between experiment and theory of thermodynamic properties such as the specific-heat difference between superconducting and normal states C_s-C_n, and the thermodynamic critical field H_c(T) support the results from the upper critical field analysis.

http://dx.doi.org/10.1016/j.physc.2007.03.177

http://dx.doi.org/10.1016/j.physc.2007.03.177