Effects of correlations on honeycomb lattice in ionic-Hubbard Model

  title={Effects of correlations on honeycomb lattice in ionic-Hubbard Model},
  author={Morad Ebrahimkhas and Z. Drezhegrighash and Elshan Soltani},
  journal={Physics Letters A},
Abstract In a honeycomb lattice the symmetry has been broken by adding an ionic potential and a single-particle gap was generated in the spectrum. We have employed the iterative perturbation theory (IPT) in dynamical mean field approximation method to study the effects of competition between U and Δ on energy gap and renormalized Fermi velocity. As we found, the competition between the single-particle gap parameter and the Hubbard potential closed the energy gap and restored the semi-metallic… 

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