Charge-density wave with imperfect nesting and superconductivity

We study the effect of the existence of the charge-density waves (CDW) on superconductivity within a mean-field approximation. When the band is slightly deformed to introduce the imperfect-nesting condition for the commensurate CDW, the metallic CDW states appear where a part of the Fermi surface is ungapped. We examine the phase diagram of the imperfect-nesting CDW states and the behavior of the superconducting critical temperature (${\mathit{T}}_{\mathit{c}}$) on it. We find that the presence of the CDW always drives the ${\mathit{T}}_{\mathit{c}}$ down.