Communications in Physics 29, 305-312 (2019)

ISSN: 0868-3166

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 nB􀀀nA 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.

DOI: 10.15625/0868-3166/29/3SI/14265

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