Minimal charge gap in the ionic Hubbard model

Abstract

We study the ionic Hubbard model at temperature T=0 within the mean-field approximation, and show that the charge gap does not close completely at the ionic-band insulator to antiferromagnetic insulator transition, contrary to previous expectations. Furthermore, we find an intermediate phase for on-site repulsions $U>U_c$ for different lattices, and calculate the phase diagram for the ionic Hubbard model with alternating U, corresponding to a Cu-O lattice.

5 pages with 7 figures; minor corrections

References in corpus (4)

• From band insulator to Mott insulator in one dimension
• A quantum Monte Carlo study of the one-dimensional ionic Hubbard model
• Nature of the Peierls- to Mott-insulator transition in 1D
• Effect of Electron Correlation on the Bragg Reflection

Cited by in corpus (6)

• Quantum critical behavior of the one-dimensional ionic Hubbard model
• Ground-state phase diagram of the one-dimensional half-filled extended Hubbard model
• Charge gaps and quasiparticle bands of the ionic Hubbard model
• Finite-temperature phase transitions in the ionic Hubbard model
• Effective Hamiltonian for a Half-filled Hubbard Chain with Alternating On-site Interactions
• Generalization of Lieb-Wu wave function inspired by one-dimensional ionic Hubbard model