Excitations in the mixed state of type-II superconductors.

Abstract

Quasiparticle excitations in the mixed state of a type-II superconductor outside the vortex cores are shown to fall into bands, and near ${\mathit{H}}_{\mathit{c}2}$ have a Landau-level type of structure. This leads to de Haas--van Alphen oscillations in the quasiparticle magnetization. Most of the pairing comes from states near the band edges and gives rise to a complicated structure of the order parameter.