Spectral microscopic mechanisms and quantum phase transitions in a 1D correlated problem

TL;DR

This paper investigates the microscopic mechanisms behind spectral weight distributions and quantum phase transitions in the one-dimensional Hubbard model, revealing the competition between insulating and metallic phases across doping levels.

Contribution

It identifies the dominant microscopic processes responsible for spectral features in the 1D Hubbard model for all on-site repulsion values, linking theory with experimental observations.

Findings

Spectral-weight distributions are generated by non-perturbative processes.

There is a competition between processes in insulating and metallic phases.

Results agree quantitatively with photoelectron spectroscopy data.

Abstract

In this paper we study the dominant microscopic processes that generate nearly the whole one-electron removal and addition spectral weight of the one-dimensional Hubbard model for all values of the on-site repulsion $U$. We find that for the doped Mott-Hubbard insulator there is a competition between the microscopic processes that generate the one-electron upper-Hubbard band spectral-weight distributions of the Mott-Hubbard insulating phase and finite-doping-concentration metallic phase, respectively. The spectral-weight distributions generated by the non-perturbative processes studied here are shown elsewhere to agree quantitatively for the whole momentum and energy bandwidth with the peak dispersions observed by angle-resolved photoelectron spectroscopy in quasi-one-dimensional compounds.