The Phase Diagram of High-Tc Cuprates

TL;DR

This paper develops a comprehensive theoretical phase diagram for hole-doped high-Tc cuprates, accurately matching experimental data and revealing the interplay between superconducting and spin-glass phases.

Contribution

It introduces a new Hamiltonian-based theory that analytically derives phase transition lines, aligning well with experimental observations and contrasting with Anderson's RVB theory.

Findings

Analytic expressions for phase transition lines match experimental data

Ground state is RVB-like, supporting a unified theoretical framework

Highlights the different mechanisms in electron- and hole-doped cuprates

Abstract

The detailed structure of the $T \times doping$ phase diagram of hole doped High-Tc superconducting cuprates is investigated from the perspective of a recently proposed comprehensive theory for these materials. Our theory is compared to Anderson's RVB theory for High-$T_c$ cuprates and it is demonstrated that the ground-eigenstate of our theory's Hamiltonian is a RVB-like state. From the Hamiltonian we derive the thermodynamic potential, as a function of convenient order parameters, through a method whose stability is carefully demonstrated. From this, we obtain analytic expressions for the transition lines delimiting the N\'eel phase, $T_N(x)$, the Spin-Glass phase, $T_{g}(x)$ and the CDW Charge Ordered phase, $T_{co}(x)$. These results, along with the previously derived expressions for the transition lines delimiting the Superconducting phase, $T_C(x)$, the Pseudogap and Strange Metal phases, $T^*(x)$ and the Fermi Liquid phase, $T_{FL}(x)$ are in excellent agreement with the experimental data from the cuprates. Our study reveals, in particular, the complementary role, which is played by the mechanisms responsible for the onset of superconducting (SC) and Spin-Glass (SG) phases in these materials. The absence of SG phases in electron doped High-Tc superconducting cuprates, strongly suggests a different SC mechanism should operate in those materials