Metal-insulator transitions in the two dimensional ionic Hubbard model within coherent potential approximation

Thi Hai Yen NGUYEN; Tuan Hoang Anh

doi:10.15625/0868-3166/23350

Author affiliations

Authors

Nguyen Thi Hai Yen Institute of Physics https://orcid.org/0000-0002-3640-8505
Hoang Anh Tuan Institute of Physics, Vietnam Academy of Science and Technology, 10 Dao Tan, Giang Vo, Hanoi, Vietnam https://orcid.org/0000-0001-8498-0541

DOI:

https://doi.org/10.15625/0868-3166/23350

Keywords:

Metal-insulator transition, Ionic Hubbard model, Coherent potential approximation

Abstract

We employ the coherent potential approximation to investigate the phase diagram of the ionic Hubbard model on the square lattice. The results show the existence of two insulating phases: a band insulator in the regime of large ionic potential $\Delta$ and small Coulomb interaction $U$, and a Mott insulator in the regime of large $U$. Between these two insulating phases, a metallic phase emerges as an intermediate state. The obtained phase diagram is compared to those on the Bethe lattice.

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