One-electron singular spectral features of the 1D Hubbard model at finite magnetic field

TL;DR

This paper investigates the singular spectral features of the one-electron spectral functions in the 1D Hubbard model at finite magnetic field, revealing how various parameters influence these features through a detailed theoretical analysis.

Contribution

It introduces a comprehensive analysis of the exponents controlling spectral features in the 1D Hubbard model at finite magnetic field, using rotated electrons and pseudofermion theory.

Findings

Defined Hubbard bands for all densities and magnetic fields

Linked electrons to pseudofermions via rotated electrons

Clarified microscopic processes in spectral functions

Abstract

The momentum, electronic density, spin density, and interaction dependences of the exponents that control the $(k,\omega)$-plane singular features of the $\sigma =\uparrow,\downarrow$ one-electron spectral functions of the 1D Hubbard model at finite magnetic field are studied. The usual half-filling concepts of one-electron lower Hubbard band and upper Hubbard band are defined for all electronic density and spin density values and the whole finite repulsion range in terms of the rotated electrons associated with the model Bethe-ansatz solution. Such rotated electrons are the link of the non-perturbative relation between the electrons and the pseudofermions. Our results further clarify the microscopic processes through which the pseudofermion dynamical theory accounts for the $\sigma $ one-electron matrix elements between the ground state and excited energy eigenstates.