  We investigate the interplay of superconductivity and the topological order
in the topological insulator (TI) formed in HgTe-CdTe quantum wells coupled to
the s-wave isotropic superconductor (SC) placed on top of CdTe layer. Proximity
effect induces superconducting correlations in TI effecting classification of
the TI electronic states. Depending on the strength of the coupling and the
initial chemical potentials in SC and TI, the edge states either (i) become
gapped, or (ii) hybridize into localized Andreev states, or else (iii) merge
with the bulk states turning the TI into an anisotropic narrow-gap
semiconductor.
