Spectral Functions of One-dimensional Models of Correlated Electrons

TL;DR

This paper calculates spectral functions of 1D correlated electron models using the Ogata-Shiba wave function, revealing a shadow band feature that persists near half-filling and is observable in experiments.

Contribution

It demonstrates the presence and robustness of the shadow band feature in spectral functions of 1D Hubbard and t-J models using analytical and numerical methods.

Findings

Shadow band feature becomes more intense near half-filling.

Feature remains well-defined for realistic U/t and J/t values.

Shadow structure should be observable in photoemission experiments.

Abstract

Using the Ogata-Shiba wave function, the spectral functions of the one-dimensional infinite U Hubbard model are calculated for various concentrations. It is shown that the ``shadow band'' feature due to 2k_F fluctuations becomes more intense close to half-filling. Comparing these results with exact diagonalization data obtained on finite clusters for the finite U Hubbard model and for the t-J model, it is also shown that this feature remains well-defined for physically reasonable values of the parameters (U/t\simeq 10, J/t\simeq 0.4). The ``shadow'' structure in the spectral functions should thus be observable in angle-resolved photoemission experiments for a variety of quasi-one dimensional compounds.