Metal-insulator transition in half-filling two-orbital Hubbard model on triangular lattice

Abstract

We have investigated the half-filling two-orbital Hubbard model on a triangular lattice by means of the dynamical mean-field theory (DMFT). The densities of states and optical conductivity clearly show the occurence of metal-insulating transition (MIT) at U${}_c$, U${}_c$=18.2, 16.8, 6.12 and 5.85 for J=0, 0.01U, U/4 and U/3, respectively. The distinct continuities of double occupation of electrons, local square moments and local susceptibility of the charge, the spin and the orbital at J > 0 suggest that the MIT is the first-order; however at J=0, the MIT is the second-order in the half-filling two-orbital Hubbard model on triangular lattices. We attribute the first-order nature of the MIT to the low symmetry of the systems with finite Hund's coupling J.

5 figures,13 pages, published version

References in corpus (6)

• Strongly Correlated Superconductivity: a plaquette Dynamical mean field theory study
• Pseudogap and Mott Transition Studied by Cellular Dynamical Mean Field Theory
• Orbital degeneracy removed by charge order in triangular antiferromagnet AgNiO2
• Dynamical mean field study of the Mott transition in the half-filled Hubbard model on a triangular lattice
• Metal-insulator transition in the two-orbital Hubbard model at fractional band fillings: Self-energy functional approach
• Ground-state valency and spin configuration of the Ni-ions in nickelates