Peculiarities of length scales in a two-orbital superconductor
  We study the spatial behaviour of coherency and magnetic field in a two-orbital superconductor. The superconducting phase transition is caused here by the on-site intra-orbital attractions (negative-U Hubbard model) and inter-orbital pair-transfer interaction. We find the critical (diverging at $T_{c}$) and non-critical (remaining finite) coherence lengths and magnetic field penetration depth for various values of hopping integrals and the strengths of intra-orbital attractions. Numerical results have been obtained for a two-dimensional square lattice. 
G. Litak, T. \"Ord, K. R\"ago, A. Vargunin
cond-mat.supr-con