Shadow band in the one-dimensional large $U$ Hubbard model

TL;DR

This paper uses the Ogata-Shiba wave-function to compute spectral functions in the 1D large U Hubbard model, revealing a detectable shadow band from spin fluctuations alongside typical Luttinger liquid features.

Contribution

It demonstrates how the Ogata-Shiba wave-function can be employed to calculate spectral functions and identify a shadow band in the 1D large U Hubbard model.

Findings

Identification of a well-defined shadow band from $2k_F$ spin fluctuations.

Spectral function exhibits both Luttinger liquid features and a prominent shadow band.

Shadow band intensity is comparable to the main band over a wide momentum range.

Abstract

We show that the factorized wave-function of Ogata and Shiba can be used to calculate the $k$ dependent spectral functions of the one-dimensional, infinite $U$ Hubbard model, and of some extensions to finite $U$. The resulting spectral function is remarkably rich: In addition to low energy features typical of Luttinger liquids, there is a well defined band, which we identify as the shadow band resulting from $2k_F$ spin fluctuations. This band should be detectable experimentally because its intensity is comparable to that of the main band for a large range of momenta.