Slave rotor approach to dynamically screened Coulomb interactions in solids

Abstract

Recent studies of dynamical screening of the electronic Coulomb interactions in solids have revived interest in lattice models of correlated fermions coupled to bosonic degrees of freedom (Hubbard-Holstein-type models). We propose a dynamical mean-field-based approach to dynamically screened Coulomb interactions. In the effective Anderson-Holstein model, a transformation to slave rotors [S. Florens and A. Georges, Phys. Rev. B 66, 165111 (2002)] is performed to decouple the dynamical part of the interaction. This transformation allows for a systematic derivation and analysis of recently introduced approximate schemes for the solution of dynamical impurity problems, in particular, the Bose factor ansatz within the dynamic atomic limit approximation (DALA) with and without Lang-Firsov correction. More importantly still, it suggests an optimized choice for a Bose factor in the sense of the variational principle of Feynman and Peierls. We demonstrate the accuracy of our scheme and present a comparison to calculations within the DALA.

15 pages, 7 figures

References in corpus (8)

• Hubbard U and Hund's Exchange J in Transition Metal Oxides: Screening vs. Localization Trends from Constrained Random Phase Approximation
• Screened Coulomb interaction in the maximally localized Wannier basis
• Efficient DMFT-simulation of the Holstein-Hubbard Model
• Optical properties of correlated materials -- Generalized Peierls approach and its application to VO2
• Combined GW and dynamical mean field theory: Dynamical screening effects in transition metal oxides
• Self-consistent slave rotor mean field theory for strongly correlated systems
• Dynamical Screening Effects in Correlated Electron Materials -- A Progress Report on Combined Many-Body Perturbation and Dynamical Mean Field Theory: "GW+DMFT"
• Materials Design using Correlated Oxides: Optical Properties of Vanadium Dioxide