Statistics of the cuprate pairon states on a square lattice

TL;DR

This paper links high-$T_c$ superconductivity parameters to the statistical behavior of pairons on a square lattice, revealing that the phase diagram features emerge from pairon disorder and correlations, differing from BCS theory.

Contribution

It introduces a statistical approach to cuprate superconductivity, connecting phase diagram features to pairon disorder and correlations, and challenges conventional BCS energy gap explanations.

Findings

Superconducting and pseudogap states are inseparable phenomena.

Critical temperature is proportional to pairon correlation energy.

Predictions align with tunneling and photoemission experiments.

Abstract

In this paper the fundamental parameters of high-$T_c$ superconductivity are shown to be connected to the statistics of pairons (hole pairs in their antiferromagnetic environment) on a square lattice. In particular, we study the density fluctuations and the distribution of the area surrounding each pairon on the scale of the antiferromagnetic correlation length $\xi_{AF}$, for the complete range of hole concentration. We show that the key parameters of the phase diagram, the $T_c$ dome, and the pseudogap temperature $T^*$, emerge from the statistical properties of the pairon disordered state. In this approach, the superconducting and the pseudogap states appear as inseparable phenomena. The condensation energy, which fixes the critical temperature, is directly proportional to the {\it correlation energy} between pairons and {\it not} to the energy gap, contrary to conventional superconductors. When the correlation energy between pairons is suppressed by fluctuations, either thermally, by disorder, or in the vortex core, the pseudogap state of disordered pairons is obtained. We attribute the unique features of cuprate superconductivity to this order-disorder transition in real space, which clearly differs from the BCS mechanism. Our predictions are in quantitative agreement with low-temperature tunneling and photoemission spectroscopy experiments.