Charge and spin gaps of the ionic Hubbard model with density-dependent hopping

Oscar A. Moreno Segura, Karen Hallberg, Armando A. Aligia

We calculate the charge gap $\Delta E_C$ and the spin gap $\Delta E_S$ of the ionic Hubbard chain including electron-hole symmetric density-dependent hopping. The vanishing of $\Delta E_C$ ($\Delta E_S$)…