Weak coupling theory of clean (d plus s)-wave superconductors

The properties of weakly coupled clean anisotropic (orthorhombic) supercond uctors with pure d and (d+s) pairing symmetry are considered We derive anal ytical and universal results for generalized BCS-Muhlschlegel parameters li ke the zero temperature gap and the specific heat discontinuity at the tran sition even for the most general situation of (d+s) pairing symmetry The pr operties of the gas of thermal excitations, the Bogoliubov quasiparticles, is studied through the temperature dependence of the quasiparticle entropy sigma(B)(0)(T), the specific heat C-B(T), the spin susceptibility chi(B)(T) , and the quasiparticle contribution K-B(T) to the electronic supercurrent response (magnetic field penetration depth), In particular we present analy tical results for these quantities in the asymptotic low temperature limit T --> 0, The experimental relevance of these results for hole-doped cuprate superconductors,vith orthorhombic crystal symmetry is discussed.