Spectral Properties of Interacting One-Dimensional Spinless Fermions

TL;DR

This paper investigates the spectral properties of a one-dimensional spinless fermion model with interactions, revealing how particle statistics influence spectral features despite identical bulk properties to related spin models.

Contribution

It clarifies the origin of spectral differences between fermionic and bosonic systems using Bethe ansatz solutions and highlights the significance of two-string solutions in high-energy spectral regimes.

Findings

Spectral features differ due to particle statistics despite identical bulk properties.

Two-string solutions contribute significantly to high-energy spectral weights.

Differences in dispersion and line shapes are explained through Bethe ansatz analysis.

Abstract

The spectral properties of the spinless fermion model with nearest-neighbor repulsive interactions on a one-dimensional lattice are investigated using the Bethe ansatz. Although its bulk quantities are exactly the same as those of the spin-1/2 XXZ chain, the difference in the statistics of particles causes substantial effects on spectral features, such as gapless points of dispersion relations and line shapes of spectral functions. In this Letter, we clarify the origin of the differences in spectral features between fermionic and bosonic systems in terms of Bethe ansatz solutions. We also confirm that the two-string solutions have considerable spectral weights in the high-energy regime.