Communications in Physics 29
, 305-312 (2019)
MOTT TRANSITION IN THE MASS IMBALANCED IONIC HUBBARD MODEL AT HALF FILLING
NGUYEN THI HAI YEN, LE DUC ANH, HOANG ANH TUAN, NGUYEN TOAN THANG AND TRAN THI THU TRANG
The Mott - Hubbard metal - insulator transition in the half-filled mass imbalanced ionic
Hubbard model is investigated using the two-site dynamical mean field theory. We find that for a
fixed mass imbalanced parameter r the critical interaction Uc increases when the ionic energy D
is increased. In the other hand, for a fixed D, Uc decreases with increasing the mass imbalance.
We also show the existence of a band insulating phase in the system for the case D 6= 0;U = 0 and
calculate the staggered charge density nBnA as a function of the interaction for different values
of the mass imbalance. Our results in the limiting cases (r = 1; D 6= 0 or/and D = 0; r 6= 1) are in
good agreement with those obtained from the full dynamical mean field theory.
Keywords: ionic Hubbard model; mass imbalance; Mott transition.
Classification numbers: 71.27.+a, 71.10.Fd, 71.30.+h.