Resonant Raman scattering effects in a nesting driven charge-density-wave insulator: exact analysis of the spinless Falicov-Kimball model with dynamical mean-field theory

TL;DR

This paper provides an exact analysis of resonant Raman scattering in a charge-density-wave insulator using the spinless Falicov-Kimball model within dynamical mean-field theory, revealing temperature-dependent effects and resonant enhancements.

Contribution

It presents an exact calculation of the Raman spectrum including all contributions for a charge-density-wave system using the Falicov-Kimball model and DMFT, with detailed polarization analysis.

Findings

Significant temperature dependence of the many-body density of states.

Large enhancement of Raman response near the charge-density-wave gap energy.

Resonant effects strongly influence the scattering spectrum.

Abstract

We calculate the total electronic Raman scattering spectrum for a system with a charge density wave on an infinite-dimensional hypercubic lattice. The problem is solved exactly for the spinless Falicov-Kimball model with dynamical mean-field theory. We include the nonresonant, mixed, and resonant contributions in three common experimental polarizations, and analyze the response functions for representative values of the energy of the incident photons. The complicated scattering response can be understood from the significant temperature dependence of the many-body density of states, and includes a huge enhancement for photon frequencies near the charge-density-wave gap energy.