Spectral function of the one-dimensional Hubbard model away from half filling

TL;DR

This paper uses advanced numerical methods to accurately compute the spectral function of a 1D Hubbard model away from half filling, revealing spin-charge separation in a real material.

Contribution

It introduces a new approach for calculating momentum-dependent spectral functions in finite open chains with high accuracy, validated against Bethe Ansatz results.

Findings

Spectral function computed with unprecedented accuracy.

Evidence of spin-charge separation in TTF-TCNQ.

Method applicable to other low-dimensional conductors.

Abstract

We calculate the photoemission spectral function of the one-dimensional Hubbard model away from half filling using the dynamical density matrix renormalization group method. An approach for calculating momentum-dependent quantities in finite open chains is presented. Comparison with exact Bethe Ansatz results demonstrates the unprecedented accuracy of our method. Our results show that the photoemission spectrum of the quasi-one-dimensional conductor TTF-TCNQ provides evidence for spin-charge separation on the scale of the conduction band width.