Optical and Magneto-optical Response of a Doped Mott Insulator

TL;DR

This paper investigates the optical, Raman, and Hall responses of doped Mott insulators using dynamical mean-field theory, revealing isosbectic points linked to charge susceptibility and contrasting coherent and incoherent metallic behaviors.

Contribution

It provides a detailed analysis of the optical and Hall responses in doped Mott insulators, highlighting the role of isosbectic points and coherence effects within the DMFT framework.

Findings

Identification of isosbectic points in optical conductivity and Hall response.

Raman scattering shows significant incoherent contributions.

Comparison between Fermi liquid and non-Fermi liquid behaviors in response functions.

Abstract

We study the optical, Raman, and ac Hall response of the doped Mott insulator within the dynamical mean-field theory ($d=\infty$) for strongly correlated electron systems. The occurence of the {\it isosbectic} point in the optical conductivity is shown to be associated with the frequency dependence of the generalized charge susceptibility. We compute the Raman response, which probes the fluctuations of the "stress tensor", and show that the scattering is characterized by appreciable incoherent contributions. The calculated ac Hall constant and Hall angle also exhibit the isosbectic points. These results are also compared with those obtained for a {\it non-FL} metal in $d=\infty$. The role of low-energy coherence (FL) or incoherence (non-FL) in determining the finite frequency response of strongly correlated metals in $d=\infty$ is discussed in detail.