Diagrammatic study of optical excitations in correlated systems

Abstract

The optical conductivity contains relevant information on the properties of correlated electron systems. In infinite dimensions, where dynamical mean field theory becomes exact, vertex corrections can be neglected and the conductivity computed from particle-hole bubbles. An interesting question concerns the nature and effect of the most relevant vertex corrections in finite-dimensional systems. A recent numerical study showed that the dominant vertex correction near an ordering instability with wave vector π comes from a vertical ladder, analogous to the Maki-Thompson diagram. Since the RPA version of this ladder diagram, dubbed π-ton, can be easily evaluated, this suggests a simple procedure for incorporating antiferromagnetic or charge density wave fluctuations into dynamical mean field estimates of the optical conductivity and related susceptibilities. We implement this procedure for the half-filled Hubbard model, considering the π-ton and a double-ladder extension of the π-ton, and reveal the spectral signatures of these vertex corrections.

arXiv comment15 pages, 13 figures

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Cited by in corpus (13)

• Impact of partially bosonized collective fluctuations on electronic degrees of freedom
• Parametrizations of local vertex corrections from weak to strong coupling: importance of the Hedin three-leg vertex
• Skewed Non-Fermi Liquids and the Seebeck Effect
• Nonequilibrium Two-Particle Self-Consistent Approach
• Dynamical Mean Field Theory extension to the nonequilibrium Two-Particle Self-Consistent approach
• Non-equilibrium evolution of the optical conductivity of the weakly interacting Hubbard model: Drude response and $\pi$-ton type vertex corrections
• Nonequilibrium DMFT approach to time-resolved Raman spectroscopy
• Displaced Drude peak from $\pi$-ton vertex corrections
• Broadening and sharpening of the Drude peak through antiferromagnetic fluctuations
• Multi-band D-TRILEX approach to materials with strong electronic correlations
• Analytical expression for $\pi$-ton vertex contributions to the optical conductivity
• Superconductivity and the quasiparticle mass enhancement near the CDW critical point using Bethe-Salpeter method: Application to cuprates
• Prototypical many-body signatures in transport properties of semiconductors