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

TL;DR

This paper explores how pseudogap phenomena and impurities independently and collectively suppress the superconducting transition temperature in hole-doped cuprates, proposing a unified framework for their effects.

Contribution

It introduces a framework treating pseudogap and impurity effects on Tc on equal footing, and investigates their impact on isotope exponent variations.

Findings

Pseudogap and impurities both significantly reduce Tc in cuprates.

A unified approach models their combined effects on superconductivity.

Disorder and hole content influence isotope exponent in high-Tc cuprates.

Abstract

Irrespective of the class they belong to, all the hole doped high-Tc cuprate superconductors show an anti-correlation 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.