The composite operator method route to the 2D Hubbard model and the cuprates

TL;DR

This review discusses using the composite operator method to solve the 2D Hubbard model and explain unconventional behaviors in underdoped high-Tc cuprate superconductors, highlighting its effectiveness in strongly correlated systems.

Contribution

It provides a comprehensive overview of the composite operator method and demonstrates its application to the 2D Hubbard model and cuprates.

Findings

Successful application to strongly correlated systems

Explanation of unconventional cuprate behaviors

Robust framework for complex materials

Abstract

In this review paper, we illustrate a possible route to obtain a reliable solution of the 2D Hubbard model and an explanation for some of the unconventional behaviours of underdoped high-$T_\text{c}$ cuprate superconductors within the framework of the composite operator method. The latter is described exhaustively in its fundamental philosophy, various ingredients and robust machinery to clarify the reasons behind its successful applications to many diverse strongly correlated systems, controversial phenomenologies and puzzling materials.