  There is a tacit assumption that multiband superconductors are essentially
the same as multigap superconductors. More precisely, it is usually assumed
that the number of excitation gaps in the single-particle energy spectrum of a
uniform superconductor determines the number of contributing bands in the
corresponding superconducting model. Here we demonstrate that contrary to this
widely accepted viewpoint, the superconducting magnetic properties are
sensitive to the number of contributing bands even when the corresponding
excitation gaps are degenerate and cannot be distinguished. In particular, we
find that the crossover between superconductivity types I and II - the
intertype regime - is strongly affected by difference between characteristic
lengths of multiple contributing condensates. The reason for this is that
condensates with diverse characteristic lengths coexisting in one system
interfere constructively or destructively, which results in multi-condensate
magnetic phenomena regardless of the presence/absence of the multigap structure
in the single-particle excitation spectrum.
