Surface Superconductivity of Dirty Two-Band Superconductors: Applications to \rm MgB₂

2003/12/01 by D. A. Gorokhov, Denis A. Gorokhov, Gorokhov, Denis A.
Physics and Astronomy · #Superconductivity in MgB2 and Alloys #cond-mat.dis-nn #cond-mat.mtrl-sci #cond-mat.supr-con

paper · pdf · doi:10.48550/arxiv.cond-mat/0312014

RevTeX, 4 pages, 1 eps figure inserted

arxiv created 2003/12/01 · arxiv updated 2009/12/01

Abstract

The minimal magnetic field H_c2 destroying superconductivity in the \it bulk of a superconductor is smaller than the magnetic field H_c3 needed to destroy \it surface superconductivity if the surface of the superconductor coincides with one of the crystallographic planes and is parallel to the external magnetic field. While for a dirty single-band superconductor the ratio of H_c3 to H_c2 is a universal temperature-independent constant 1.6946, for dirty two-band superconductors this is not the case. I show that in the latter case the interaction of the two bands leads to a novel scenario with the ratio H_c3/H_c2 varying with temperature and taking values larger and smaller than 1.6946. The results are applied to \rm MgB₂ and are in agreement with recent experiments [A. Rydh \it et al., cond-mat/0307445].

Related

• Upper critical field H_c2 in two-band superconductor
• The microscopic theory of the upper critical field Hc2 in two-band systems in the magnetic field directed parallel and perpendicular to the plane (ab). Application to MgB2
• Superconductivity Above H_c2 as a Probe for Niobium RF-Cavity Surfaces
• Persistence of superconductivity in thin shells beyond H_c1
• Effect of an electric field on the surface superconductivity