Existence of charge-density waves in two-dimensional ionic Hubbard model

Abstract

We rigorously investigated the charge-charge correlation function of the ionic Hubbard model in two dimensions by reflection positivity. We prove the existence of charge-density waves for large staggered potential $\Delta$ (i.e., $\frac{\Delta }{2}+2V>U$) at low temperatures, where $U$ and $V$ are the on-site and nearest-neighbor Coulomb repulsions, respectively. The results are consistent with previous numerical simulation results. We argue that the absence of charge-density waves for $\Delta =0$ and $U$ are large enough (i.e., $U>\frac{\Delta }{2}$+2V).

32 pages. v2: typos corrected

References in corpus (5)

• Quantum Monte Carlo Study of an Interaction-Driven Band Insulator to Metal Transition
• Metallic phase in the two-dimensional ionic Hubbard model
• Exploring competing density order in the ionic Hubbard model with ultracold fermions
• Quantum Griffiths inequalities
• Long-range charge order in the extended Holstein--Hubbard model

Cited by in corpus (1)

• Self-Energy Dispersion in the Hubbard Model