SUPERCONDUCTIVITY IN 2-BAND MODEL

Superconductivity in two-band models involving non s-wave pairing is i nvestigated. We consider the following case: one band has s-wave pairi ng interaction and the other has non s-wave pairing interaction, and o nly s-wave Cooper pairs can be transferred between bands. Possible app earance of non s-wave superconducting order parameter in an s-wave sup erconducting state and its onset temperature are discussed. The non s- wave order parameter is suppressed by s-wave superconductivity, and ca nnot appear unless the non s-wave pairing interaction is stronger than critical value. We also consider the appearance of s-wave superconduc ting order parameter in a non s-wave superconducting state. In this ca se, the s-wave order parameter can always appear on lowering temperatu re. Temperature dependence of the order parameters and the specific he at are shown in a simple case.