Phase Diagram of High-T_c Superconductors from a Field Theory Model

TL;DR

This paper uses a field theory model and renormalization group approach to map the phase diagram of high-T_c cuprate superconductors, revealing competing magnetic and superconducting phases at Van Hove filling.

Contribution

It introduces a field theory-based method to analyze the phase diagram of the t-t' Hubbard model, highlighting the competition between antiferromagnetism and d-wave superconductivity.

Findings

Identifies ferromagnetic, antiferromagnetic, and d-wave superconducting phases.

Shows antiferromagnetism and d-wave superconductivity originate from the same interactions.

Maps the phase diagram at Van Hove filling with competing orders.

Abstract

The renormalization group approach to correlated fermions is used to determine the phase diagram of the oxide cuprates modeled by the t-t' Hubbard model at the Van Hove filling. Spin-dependent interactions give rise to instabilities corresponding to ferromagnetic, antiferromagnetic and d-wave superconducting phases. Antiferromagnetism and d-wave superconductivity arise from the same interactions, and compete in the same region of parameter space.