Orientational symmetry-breaking correlations in square lattice t-J model

TL;DR

This paper investigates how the square lattice t-J model exhibits a strong tendency for orientational symmetry breaking, especially near certain Fermi surface configurations, which may explain some properties of high-Tc cuprates.

Contribution

It introduces a method to quantify the response of hole-hole correlations to anisotropy, revealing conditions under which orientational symmetry breaking is enhanced.

Findings

Strong response to anisotropy near specific band parameters

Correlation develops when Fermi surface approaches (pi,0) and (0,pi)

Properties of high-Tc cuprates can be explained by symmetry breaking

Abstract

We study a tendency to orientational symmetry breaking of the square lattice t-J model by applying the exact diagonalization technique. We introduce a small external anisotropy to t and J, and calculate the induced anisotropy of hole-hole correlations as a response. It is found that the response is strongly enhanced for particular band parameters, meaning that the system has a strong tendency to orientational symmetry breaking. The analysis of the momentum distribution function indicates that the correlation develops when the Fermi surface is close to (pi,0) and (0,pi). Some properties of high-Tc cuprates previously attributed to stripes can also be understood from orientational symmetry breaking alone.