  In the usual Ginzburg-Landau theory the critical value of the ratio of two
fundamental length scales in the thery $\kappa_c=1/\sqrt{2}$ separates regimes
of type-I and type-II superconductivity. The latter regime possess
thermodynamically stable vortex excitations which interact with each other
repulsively and tend to form vortex lattices. It was shown in [5] that this
dichotomy in broken in U(1)xU(1) Ginzburg-Landau models which possess three
fundamental length scales which results in the existence of a distinct phase
with vortex excitations which interact attractively at large length scales and
repulsively at shorter distances. Here we briefly review these results in
particular discussing the role of interband Josephson coupling and the case
where only one band is superconducting while superconductivity in another band
is induced by interband proximity effect. The report is partially based on E.
Babaev, J. Carlstrom, J. M. Speight arXiv:0910.1607.
