Spectral properties of the one-dimensional Hubbard model

TL;DR

This paper investigates the spectral properties of the one-dimensional Hubbard model using quantum Monte Carlo simulations and maximum entropy methods, revealing dispersive bands and near-conformal charge behavior.

Contribution

It provides detailed spectral analysis and spin-charge velocity measurements for the 1-D Hubbard model, with high accuracy and validation against sum-rules.

Findings

Dispersive cosine-like bands characterize one-particle excitations.

Spin and charge velocities are quantified, indicating near-conformal charge c≈1.

Sum-rule for spin-excitations is accurately fulfilled with minimal deviations.

Abstract

The spectral properties of the 1-D Hubbard model are obtained from quantum Monte Carlo simulations using the maximum entropy method. The one-particle excitations are characterized by dispersive cosine-like bands. Velocities for spin- and charge excitations are obtained that lead to a conformal charge c=0.98 +/- 0.05 for the largest system simulated (N=84). An exact sum-rule for the spin-excitations is fulfilled accurately with deviations of at most 10% only around 2 kF.