Mott-Hubbard metal-insulator transition in nonbipartite lattices

Abstract

We reinterpret the Hubbard model in terms of doubly occupied sites and empty sites with an attractive interaction U whose pairing leads to the Mott-Hubbard transition. We develop a mean-field theory for this pairing which in a triangular lattice at T-0 leads to a first-order transition from a spiral, incommensurate metal to a commensurate insulator at (7 -5.27/ where a charge gap (-0.085/) opens up. We also discuss the effect of fluctuations.

Equilibration and prethermalization in the Bose-Hubbard and Fermi-Hubbard models

“…Fortunately, however, it suffices to consider a few elements only. If we introducê p µ = |1 µ 2| andĥ µ = |0 µ 1| as local particle and hole operators (these excitations are sometimes [35,39,85] called doublons and holons), all the interesting physics can be captured by their correlation functions (for µ = ν)…”

Importance of anisotropy in the spin-liquid candidate Me3EtSb[Pd(dmit)2]2

“…In addition, for generic values of the hopping parameters magnetic states with generic spiral order may be expected and indeed can be obtained within mean-field approaches, like for instance the Hartree-Fock (HF) approximation. 13,14 Here, we approach this problem by implementing correlated variational wave functions which describe both spinliquid states and magnetic states with generic ordering vectors. In this way, we are able to treat spiral order and paramagnetic states at the same level of theory and therefore have a sensible comparison of their energies versus U .…”

Electron correlation in the two-dimensional triangle lattice ofNaxCoO2

“…In other words, every lattice site is occupied by S=1/2. If we employ the Hubbard model within a mean field approximation as the basis for explaining the magnetism of such system; [31,32,33] …”