Shadow Band in the One-Dimensional Infinite-UHubbard Model

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.