The Field Perturbation Theory of the Double Correlated Phase in High Temperature Superconductors

TL;DR

This paper develops a field perturbation theory framework for the double-correlated phase in high-temperature superconductors, defining key states and excitations, and highlighting the importance of Hartree diagrams in understanding pseudogap and superconductivity.

Contribution

It introduces a novel field perturbation approach to analyze the double-correlated phase, including the ground state, excitations, and Hamiltonian derivation, emphasizing the role of Hartree diagrams.

Findings

Hartree diagram is significant for pseudogap and superconductive order

Constructed the unperturbed Hamiltonian and propagators

Identified the ground state and quasi-particle excitations

Abstract

The Double-Correlated phase in HTSC, and its treatment by field perturbation theory, is established. In particular, we define the ground state, the quasi-particle excitations, and construct an appropriate field. We also derive the unperturbed Hamiltonian, and the propagators for the unperturbed state. Then we discuss the perturbation Hamiltonian, and show that the Hartree diagram is significant for both the pseudogap and the superconductive order parameter, and suggest that it yields the major contribution to these parameters.