Magnetic field dependence of the density of states for thin films of d-wave superconductors

Abstract

The density of states (DOS) produced by the vortices in thin films of superconductors with the anisotropic pairing is studied in the low temperature limit using the semiclassical approach. For ultrathin films of thickness d ⪡ λ (where λ is the London penetration depth) the magnetic field dependence of the spatially averaged DOS N( B) at the Fermi level appears to be qualitatively different from the one calculated previously for bulk superconductors in Ref.[1]. The N( B) behavior is shown to depend essentially on the ratio of the intervortex distance to the effective penetration depth λ eff = λ 2/ d. The peculiarities of DOS produced by 2D pancake vortices (far away from the normal cores) in d-wave layered superconductors are also discussed.