Hubbard model with bond-charge interaction on a triangular lattice: a renormalization group study

TL;DR

This study applies a real space renormalization group approach to analyze the Hubbard model with bond-charge interaction on a triangular lattice at half-filling, revealing effects of lattice geometry and hopping sign asymmetry.

Contribution

It provides a detailed RG analysis of the Hubbard model with bond-charge interaction on a triangular lattice, including ground state energy and local moment calculations across parameter space.

Findings

RG results match exact limits

Lattice geometry influences intermediate behavior

Sign reversal asymmetry affects physical properties

Abstract

We have studied the Hubbard model with bond-charge interaction on a triangular lattice for a half-filled band. At the point of particle-hole symmetry the model could be analyzed in detail in two opposite regimes of the parameter space. Using a real space renormalization group we calculate the ground state energy and the local moment over the whole parameter space. The RG results obey the exact results in the respective limits. In the intermediate region of the parameter space the RG results clearly show the effects of the non-bipartite geometry of the lattice as well as the absence of symmetry in the reversal of the sign of the hopping matrix element.