T/sub c/ enhancement in superconductor and spin-density-wave coexistence

The interplay of superconductivity and spin-density waves in a two-band system with imperfect nesting and interband coupling is analyzed. Within this model, enhancement of the superconducting critical transition temperature is found. The influence of the interband coupling on this enhancement is presented in detail. The possible connections with the high-T/sub c/ oxidic systems are also discussed. The obtained curves of T/sub c/ versus the excess carrier concentration fit well with both La-Ba-Cu-O and Y-Ba-Cu-O cases