Penetration-depth anisotropy in two-band superconductors

Abstract

The anisotropy of the London penetration depth is evaluated for two-band superconductors with arbitrary interband and intraband scattering times. If one of the bands is clean and the other is dirty in the absence of interband scattering, the anisotropy is dominated by the Fermi surface of the clean band and is weakly temperature dependent. The interband scattering also suppresses the temperature dependence of the anisotropy.