Pair Breaking, Pseudogap, and Superconducting Tc of Hole-Doped Cuprates: Interrelations and Implications

Irrespective of the class they belong to, all the hole-doped high-transition temperature (Tc) cuprate superconductors show an anticorrelation between the superconducting transition temperature and the characteristic pseudogap energy in the underdoped region. The doping-dependent pseudogap in the quasiparticle spectral density is believed to remove low-energy electronic states and thereby reduce the superconducting condensate. Impurities within the CuO2 plane, on the other hand, break Cooper pairs in the unitarity limit and diminish superfluid density. Both pseudogap in pure cuprates and impurity scattering in disordered cuprates reduces Tc very effectively. In this study, we have compared and contrasted the mechanisms of Tc degradation due to pseudogap and impurity scattering in hole-doped cuprates. We have suggested a framework where both these factors can be treated on somewhat equal footing. Beside impurity and pseudogap-dependent superconducting transition temperature, the proposed scenario has been employed to investigate the disorder and hole content-dependent isotope exponent in high-Tc cuprates in this work.