Modern Physics Letters B 26, 1150016 (2012)

SCI

Phase transition in the half-filled ionic Hubbard model: mean-field slave boson study

Duc-Anh Le, Anh-Tuan Hoang

We study electronic phase transitions in the half-filled ionic Hubbard model with an on-site Coulomb repulsion U and an ionic energy ∆ by using the Kotliar–Ruckenstein slave-boson theory. Assuming a paramagnetic solution, we show that for any non-zero values of ∆, with increasing U the system undergoes a transition from band-insulator to Mott-insulator. Our results have implied the absence of a metallic phase between the band and the Mott insulator phases.