On X-ray-singularities in the f-electron spectral function of the Falicov-Kimball model

Abstract

The f-electron spectral function of the Falicov-Kimball model is calculated within the dynamical mean-field theory using the numerical renormalization group method as the impurity solver. Both the Bethe lattice and the hypercubic lattice are considered at half filling. For small U we obtain a single-peaked f-electron spectral function, which --for zero temperature-- exhibits an algebraic (X-ray) singularity ($|\omega {|}^{-\alpha }$) for $\omega \to 0$. The characteristic exponent $\alpha$ depends on the Coulomb (Hubbard) correlation U. This X-ray singularity cannot be observed when using alternative (Keldysh-based) many-body approaches. With increasing U, $\alpha$ decreases and vanishes for sufficiently large U when the f-electron spectral function develops a gap and a two-peak structure (metal-insulator transition).

8 pages, 8 figures, revtex

References in corpus (4)

• Exact solution of the Falicov-Kimball model with dynamical mean-field theory
• Finite temperature numerical renormalization group study of the Mott-transition
• Magnetism and Phase Separation in the Ground State of the Hubbard Model
• High Energy Dynamics of the Single Impurity Anderson Model

Cited by in corpus (9)

• The numerical renormalization group method for quantum impurity systems
• Simple ${\mathbb{Z}}_2$ lattice gauge theories at finite fermion density
• Mott transition of fermionic mixtures with mass imbalance in optical lattices
• Influence of disorder on the transport properties of heavy-fermion systems
• Realistic quantum critical point in one-dimensional two-impurity models
• Exact solution of a variety of X-ray probes in the Falicov-Kimball model with dynamical mean-field theory
• Transport properties of heavy-fermion systems
• X-Ray Photoemission Spectroscopy in the Falicov-Kimball model
• Comparison Between the f-Electron and Conduction-Electron Density of States in the Falicov-Kimball Model at Low Temperature