The dynamical mean-field theory formalism to describe nonresonant inelastic light and x-ray scattering in a charge-density-wave phase is developed and applied to the spinless Falicov-Kimball model on an infinite-dimensional hypercubic lattice at half-filling. At zero temperature, the charge gap in the density of states is exactly equal to $U$ ; increasing the temperature rapidly fills the gap with subgap states. The nonresonant response function for Raman and inelastic x-ray scattering shows peaks connected with transitions over the gap and transitions that involve subgap states; in addition, the spectra have significant changes in shape as the temperature is raised from zero to ${T}_{c}$ . In the case of x-ray scattering (when both energy and momentum are transferred), the response function illustrates features of dynamical screening (vertex corrections) in the different (nonresonant) symmetry channels ( ${A}_{1g}$ and ${B}_{1g}$ ); dynamical screening is also present in the ${A}_{1g}$ Raman signal. Finally, we derive and verify the first-moment sum rules for the (nonresonant) Raman and inelastic x-ray response functions in the charge-density-wave phase and we discuss experimental implications for how the sum rules might be employed in data analysis.The dynamical mean-field theory formalism to describe nonresonant inelastic light and x-ray scattering in a charge-density-wave phase is developed and applied to the spinless Falicov-Kimball model on an infinite-dimensional hypercubic lattice at half-filling. At zero temperature, the charge gap in the density of states is exactly equal to $U$; increasing the temperature rapidly fills the gap with subgap states. The nonresonant response function for Raman and inelastic x-ray scattering shows peaks connected with transitions over the gap and transitions that involve subgap states; in addition, the spectra have significant changes in shape as the temperature is raised from zero to ${T}_{c}$. In the case of x-ray scattering (when both energy and momentum are transferred), the response function illustrates features of dynamical screening (vertex corrections) in the different (nonresonant) symmetry channels (${A}_{1g}$ and ${B}_{1g}$); dynamical screening is also present in the ${A}_{1g}$ Raman signal. Finally, we derive and verify the first-moment sum rules for the (nonresonant) Raman and inelastic x-ray response functions in the charge-density-wave phase and we discuss experimental implications for how the sum rules might be employed in data analysis.

arXiv:0809.5284Physical Review BMar 27, 20094 citations

Inelastic x-ray scattering as a probe of electronic correlations

Thomas Devereaux, Gary McCormack, James K. Freericks

We construct an exact dynamical mean-field theory for nonresonant inelastic light scattering in the infinite-dimensional Falicov-Kimball model, which can be tuned through a quantum critical metal-insulator transition. Due to the projection of the polarization orientations onto different regions of the Brillouin zone and due to the transfer of energy and momentum from the weakly to the strongly correlated charge excitations, the nature of the dynamics can be naturally interpreted as strongly temperature-dependent low-energy particle-hole excitations and weakly temperature-dependent high-energy charge-transfer excitations which depend delicately on the electronic correlations. These results can be used to provide important information concerning the evolution of charge dynamics in different regions of the Brillouin zone.We construct an exact dynamical mean-field theory for nonresonant inelastic light scattering in the infinite-dimensional Falicov-Kimball model, which can be tuned through a quantum critical metal-insulator transition. Due to the projection of the polarization orientations onto different regions of the Brillouin zone and due to the transfer of energy and momentum from the weakly to the strongly correlated charge excitations, the nature of the dynamics can be naturally interpreted as strongly temperature-dependent low-energy particle-hole excitations and weakly temperature-dependent high-energy charge-transfer excitations which depend delicately on the electronic correlations. These results can be used to provide important information concerning the evolution of charge dynamics in different regions of the Brillouin zone.

arXiv:cond-mat/0305140Physical review. B, Condensed matterAug 8, 200310 citations

Phase transitions in the three-dimensional Falicov–Kimball model

Martin Žonda, Pavol Farkašovský, Hana Čenčariková

Solid State CommunicationsSep 1, 200918 citations

U

; increasing the temperature rapidly fills the gap with subgap states. The nonresonant response function for Raman and inelastic x-ray scattering shows peaks connected with transitions over the gap and transitions that involve subgap states; in addition, the spectra have significant changes in shape as the temperature is raised from zero to

{T}_{c}

. In the case of x-ray scattering (when both energy and momentum are transferred), the response function illustrates features of dynamical screening (vertex corrections) in the different (nonresonant) symmetry channels (

{A}_{1g}

and

{B}_{1g}

); dynamical screening is also present in the

{A}_{1g}

Raman signal. Finally, we derive and verify the first-moment sum rules for the (nonresonant) Raman and inelastic x-ray response functions in the charge-density-wave phase and we discuss experimental implications for how the sum rules might be employed in data analysis.