Effect of electron correlation on superconducting pairing symmetry

The role of electron correlation on different pairing symmetries are discussed in details where the electron correlation has been treated within the slave boson formalism. It is shown that for a pure s or pure d wave pairing symmetry, the electronic correlation suppresses the s wave gap magnitude (as well as the Tc) at a faster rate than that for the d wave gap. On the other hand, a complex order parameter of the form (s+id) shows anomalous temperature dependence. For example, if the temperature (Tcd) at which the d wave component of the complex order parameter vanishes happens to be larger than that for the s wave component (Tcs), then the growth of the d wave component is arrested with the onset of the s wave component of the order parameter. In this mixed phase however, we find that the suppression in different components of the gap as well as the corresponding Tc due to Coulomb correlation are very sensitive to the relative pairing strengths of s and d channels as well as the underlying lattice. Interestingly enough, in such a scenario (for a case of Tcs>Tcd)the gap magnitude of the d wave component increases with electron correlation but not Tcd for certain values of electron correlation. However, this never happens in case of the s wave component. (orig.)