Slave-boson field fluctuation approach to the extended Falicov-Kimball model: charge, orbital, and excitonic susceptibilities

Abstract

Based on the SO(2)-invariant slave-boson scheme, the static charge, orbital, and excitonic susceptibilities in the extended Falicov-Kimball model are calculated. Analyzing the phase without long-range order we find instabilities towards charge order, orbital order, and the excitonic insulator (EI) phase. The instability towards the EI is in agreement with the saddle-point phase diagram. We also evaluate the dynamic excitonic susceptibility, which allows the investigation of uncondensed excitons. We find qualitatively different features of the exciton dispersion at the semimetal-EI and at the semiconductor-EI transition supporting a crossover scenario between a BCS-type electron-hole condensation and a Bose-Einstein condensation of preformed bound electron-hole pairs.

8 pages, 9 figures, final version

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• Hartree-Fock study of electronic ferroelectricity in the Falicov-Kimball model with $f$-$f$ hopping
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Cited by in corpus (22)

• Excitonic condensation in systems of strongly correlated electrons
• Electron-hole pair condensation at the semimetal-semiconductor transition: a BCS-BEC crossover scenario
• A BCS-BEC crossover in the extended Falicov-Kimball model: Variational cluster approach
• Excitonic Instability at the Spin-State Transition in the Two-Band Hubbard Model
• Chiral charge order in 1$T$-TiSe${}_2$: importance of lattice degrees of freedom
• Evidences for the exciton gas phase and its condensation in monolayer 1T-ZrTe2
• Exact-diagonalization study of exciton condensation in electron bilayers
• Competition between excitonic charge and spin density waves: Influence of electron-phonon and Hund's rule couplings
• Excitonic resonances in the 2D extended Falicov-Kimball model
• A New Era of Excitonic Insulators
• Nonequilibrium dynamics in the pump-probe spectroscopy of excitonic insulators
• Electric and magnetic multipoles and bond orders in excitonic insulators
• Excitonic phase transition in the extended three-dimensional Falicov-Kimball model
• Spectral properties of excitons in the bilayer graphene
• Probing phase coherence via density of states for strongly correlated excitons
• Phase coherence and spectral functions in the two-dimensional excitonic systems
• Excitonic Tunneling in the AB-bilayer Graphene Josephson Junctions
• Exciton formation in strongly correlated electron-hole systems near the semimetal-semiconductor transition
• Linear response within the projection-based renormalization method: Many-body corrections beyond the random phase approximation
• Density of states and excitonic condensation in the double layer correlated systems
• Excitonic gap formation in neutral bilayer structures
• Two band model for coherent excitonic condensates