High Tc Superconductors -- A Variational Theory of the Superconducting State

TL;DR

This paper employs a variational approach to study the d-wave superconducting state in high Tc cuprates, revealing how strong correlations influence pairing and phase coherence, with results aligning well with experimental observations.

Contribution

It introduces a detailed variational theory capturing the doping-dependent behavior of key superconducting properties in high Tc cuprates, including several experimentally verified predictions.

Findings

Pairing scale decreases monotonically with hole doping.

Superconducting order parameter exhibits a non-monotonic dome.

Quantitative agreement with experimental data on multiple observables.

Abstract

We use a variational approach to gain insight into the strongly correlated d-wave superconducting state of the high Tc cuprates at T=0. We show that strong correlations lead to qualitatively different trends in pairing and phase coherence: the pairing scale decreases monotonically with hole doping while the SC order parameter shows a non-monotonic dome. We obtain detailed results for the doping-dependence of a large number of experimentally observable quantities, including the chemical potential, coherence length, momentum distribution, nodal quasiparticle weight and dispersion, incoherent features in photoemission spectra, optical spectral weight and superfluid density. Most of our results are in remarkable quantitative agreement with existing data and some of our predictions, first reported in Phys. Rev. Lett. {\bf 87}, 217002 (2001), have been recently verified.