Excitonic Insulator State of the Extended Falicov-Kimball Model in the Cluster Dynamical Impurity Approximation

Abstract

We comparatively study the excitonic insulator state in the extended Falicov-Kimball model (EFKM, a spinless two-band model) on the two-dimensional square lattice using the variational cluster approximation (VCA) and the cluster dynamical impurity approximation (CDIA). In the latter, the particle-bath sites are included in the reference cluster to take into account the particle-number fluctuations in the correlation sites. We thus calculate the particle-number distribution, order parameter, ground-state phase diagram, anomalous Green's function, and pair coherence length, thereby demonstrating the usefulness of the CDIA in the discussion of the excitonic condensation in the EFKM.

6 pages, 5 figures, J. Phys. Soc. Jpn. (in press)

References in corpus (18)

• Evidence for an excitonic insulator phase in 1T-TiSe${}_2$
• Variational cluster approach to correlated electron systems in low dimensions
• Excitonic Bose-Einstein condensation in Ta2NiSe5 above room temperature
• Self-energy-functional approach: Analytical results and the Mott-Hubbard transition
• Variational cluster approach to spontaneous symmetry breaking: The itinerant antiferromagnet in two dimensions
• Spontaneous exciton condensation in 1T-TiSe2: a BCS-like approach
• On the possibility of an excitonic insulator at the semiconductor-semimetal transition
• First order Mott transition at zero temperature in two dimensions: Variational plaquette study
• Bound state formation and nature of the excitonic insulator phase in the extended Falicov-Kimball model
• Spin excitations in the excitonic spin-density-wave state of the iron pnictides
• Impact of Electron-Hole Correlations on the 1T-TiSe2 Electronic Structure
• Hartree-Fock study of electronic ferroelectricity in the Falicov-Kimball model with $f$-$f$ hopping
• Charge-density wave induced by combined electron-electron and electron-phonon interactions in 1$T$-TiSe${}_2$: A variational Monte Carlo study
• Phase diagram of exciton condensate in doped two-band Hubbard model
• Orbital diamagnetic susceptibility in excitonic condensation phase
• Electric and magnetic multipoles and bond orders in excitonic insulators
• Low-energy excitation spectra in the excitonic phase of cobalt oxides
• Metal-Insulator Transition of Dirac Fermions: Variational Cluster Study

Cited by in corpus (2)

• Photoinduced electron-electron pairing in the extended Falicov-Kimball model
• Extended Falicov-Kimball model: Exact solution for finite temperatures