An extended Falicov-Kimball model on a triangular lattice

Abstract

The combined effect of frustration and correlation in electrons is a matter of considerable interest of late. In this context a Falicov-Kimball model on a triangular lattice with two localized states, relevant for certain correlated systems, is considered. Making use of the local symmetries of the model, our numerical study reveals a number of orbital ordered ground states, tuned by the small changes in parameters while quantum fluctuations between the localized and extended states produce homogeneous mixed valence. The inversion symmetry of the Hamiltonian is broken by most of these ordered states leading to orbitally driven ferroelectricity. We demonstrate that there is no spontaneous symmetry breaking when the ground state is inhomogeneous. The study could be relevant for frustrated systems like $Gd{I}_2$, $NaTi{O}_2$ (in its low temperature C2/m phase) where two Mott localized states couple to a conduction band.

6 pages, 8 figures

References in corpus (10)

• Superconductivity in Cu_xTiSe_2
• Evidence for an excitonic insulator phase in 1T-TiSe${}_2$
• Orbitally-driven Peierls state in spinels
• Emergence of Fermi pockets in an excitonic CDW melted novel superconductor
• Low-lying quasiparticle states and hidden collective charge instabilities in parent cobaltate superconductors (NaxCoO2)
• Frustration and entanglement in the $t_{2g}$ spin--orbital model on a triangular lattice: valence--bond and generalized liquid states
• Dimer phases in quantum antiferromagnets with orbital degeneracy
• GdI_2: A New Ferromagnetic Excitonic Solid?
• Magnetic properties of doped GdI2
• Ground state phase diagram of a spinless, extended Falicov-Kimball model on the triangular lattice

Cited by in corpus (12)

• Order, criticality and excitations in the extended Falicov-Kimball model
• Study of ground state phases for spin-1/2 Falicov-Kimball model on a triangular lattice
• Hofstadter butterfly in the Falicov-Kimball model on some finite 2D lattices
• Thermodynamic studies of the two dimensional Falicov-Kimball model on a triangular lattice
• Phase transitions in a spinless, extended Falicov-Kimball model on the triangular lattice
• Orbital Magnetic Field Driven Metal-Insulator Transition in Spinless Extended Falicov-Kimball Model on A Triangular Lattice
• Exciton condensation in an extended spinless Falicov Kimball model in the presence of orbital magnetic fields
• Extended Falicov-Kimball model: Hartree-Fock vs DMFT approach
• Metal-Insulator Transition and Band Magnetism in the Spin-$1/2$ Falicov-Kimball Model on A Triangular Lattice with External Magnetic Field
• The Role of Intra- and Inter-site exchange correlations in the Extended Falicov-Kimball Model on a Triangular Lattice
• Classical and quantum liquids induced by quantum fluctuations
• Extended Falicov-Kimball model at weak onsite and intersite Coulomb interactions