Real-space dynamical mean-field theory of Friedel oscillations in strongly correlated electron systems

TL;DR

This paper investigates how electronic correlations influence Friedel oscillations and screening in the Hubbard model using real-space dynamical mean-field theory, revealing suppression of oscillations in the Mott insulator phase.

Contribution

It applies real-space dynamical mean-field theory with quantum Monte Carlo and NRG to study impurity screening and Friedel oscillations in strongly correlated systems.

Findings

Friedel oscillation amplitudes decrease with interaction strength in the Fermi liquid phase.

Screening charge remains finite even in the Mott insulator regime.

Friedel oscillations are absent in the Mott insulator phase.

Abstract

We study Friedel oscillations and screening effects of the impurity potential in the Hubbard model. Electronic correlations are accounted for by solving the real-space dynamical mean-field theory equations using the continuous time quantum Monte-Carlo simulations at finite temperatures and using a homogeneous self-energy approximation with the numerical renormalization group at zero temperature. We find that in the Fermi liquid phase both the amplitudes of Friedel oscillations and the screening charge decrease with increasing the interaction and follow the behavior of the Fermi liquid renormalization factor. Inside the Mott insulator regime the Friedel oscillations are absent but the residual screening charge remains finite.