Minisubbands in electron excitation spectra of layered short-coherence-length superconductors

Quasiparticle excitation spectra of short-coherence-length layered superconductors ((Formula presented)) are considered as-suming a periodic alternation of the superconducting order parameter (Formula presented) versus the lateral coordinate (Formula presented) in the (Formula presented) direction. The found self-consistent solution suggests that the electron-hole Andreev scattering in such a periodic (Formula presented) causes the appearance of minisubbands in the electron spectrum of (Formula presented), in a "clean" limit manifested as periodic spikes in the density of electron states at energies (Formula presented) ((Formula presented) is the energy gap amplitude; (Formula presented) is a natural number).