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Title: Correlated Insulated Phase Suggests Bond Order between Band and Mott Insulators in Two Dimensions

Abstract

We investigate the ground state phase diagram of the half-filled repulsive Hubbard model in two dimensions in the presence of a staggered potential ?, the so-called ionic Hubbard model, using cluster dynamical mean field theory. We find that for large Coulomb repulsion, U , the system is a Mott insulator (MI). For weak to intermediate values of ?, on decreasing U, the Mott gap closes at a critical value Uc1(?) beyond which a correlated insulating phase with possible bond order (BO) is found. Further, this phase undergoes a first-order transition to a band insulator (BI) at Uc2(?) with a finite charge gap at the transition. For large ?, there is a direct first-order transition from a MI to a BI with a single metallic point at the phase boundary

Authors:
 [1];  [1]
  1. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Science (SC)
OSTI Identifier:
930843
DOE Contract Number:  
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 98
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; COULOMB FIELD; GROUND STATES; HUBBARD MODEL; MEAN-FIELD THEORY; PHASE DIAGRAMS; ELECTRICAL INSULATORS; ENERGY GAP; PHASE TRANSFORMATIONS; Mott Insulators

Citation Formats

Kancharla, Srivenkateswara S, and Dagotto, Elbio R. Correlated Insulated Phase Suggests Bond Order between Band and Mott Insulators in Two Dimensions. United States: N. p., 2007. Web. doi:10.1103/PhysRevLett.98.016402.
Kancharla, Srivenkateswara S, & Dagotto, Elbio R. Correlated Insulated Phase Suggests Bond Order between Band and Mott Insulators in Two Dimensions. United States. doi:10.1103/PhysRevLett.98.016402.
Kancharla, Srivenkateswara S, and Dagotto, Elbio R. Mon . "Correlated Insulated Phase Suggests Bond Order between Band and Mott Insulators in Two Dimensions". United States. doi:10.1103/PhysRevLett.98.016402.
@article{osti_930843,
title = {Correlated Insulated Phase Suggests Bond Order between Band and Mott Insulators in Two Dimensions},
author = {Kancharla, Srivenkateswara S and Dagotto, Elbio R},
abstractNote = {We investigate the ground state phase diagram of the half-filled repulsive Hubbard model in two dimensions in the presence of a staggered potential ?, the so-called ionic Hubbard model, using cluster dynamical mean field theory. We find that for large Coulomb repulsion, U , the system is a Mott insulator (MI). For weak to intermediate values of ?, on decreasing U, the Mott gap closes at a critical value Uc1(?) beyond which a correlated insulating phase with possible bond order (BO) is found. Further, this phase undergoes a first-order transition to a band insulator (BI) at Uc2(?) with a finite charge gap at the transition. For large ?, there is a direct first-order transition from a MI to a BI with a single metallic point at the phase boundary},
doi = {10.1103/PhysRevLett.98.016402},
journal = {Physical Review Letters},
number = ,
volume = 98,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}