Spin and Charge Structure Factor of the 2-d Hubbard Model

TL;DR

This paper calculates the spin and charge structure factors of the 2D Hubbard model near half-filling using a slave boson approach, revealing how these factors evolve with interaction strength, electron density, and temperature.

Contribution

It introduces a spin-rotation invariant six-slave boson method to analyze the structure factors, providing new insights and comparisons with existing Quantum Monte Carlo and variational results.

Findings

Charge structure factor peaks at the zone corner and decreases with interaction and temperature.

Spin structure factor shows incommensurate peaks developing with increasing interaction.

Good agreement with Quantum Monte Carlo and variational calculations.

Abstract

The spin and charge structure factors are calculated for the Hubbard model on the square lattice near half-filling using a spin-rotation invariant six-slave boson representation. The charge structure factor shows a broad maximum at the zone corner and is found to decrease monotonically with increasing interaction strength and electron density and increasing temperature. The spin structure factor develops with increasing interaction two incommensurate peaks at the zone boundary and along the zone diagonal. Comparison with results of Quantum Monte Carlo and variational calculations is carried out and the agreement is found to be good. The limitations of an RPA-type approach are pointed out.