Band and Mott Insulators and Superconductivity in Honeycomb-Lattice Ionic-Hubbard Model
Superconductivity
2015-06-11 v1 Strongly Correlated Electrons
Abstract
Motivated by superconductivity (SC) in layered nitrides, we study an ionic-Hubbard model on a honeycomb lattice, which consists of two sublattices with an energy-level offset, by using an optimization variational Monte Carlo method. Parameter values for the Coulomb interaction and the energy-level offset, to realize a band insulator in non-doped state, are evaluated, and the SC state is investigated in a carrier-doped band insulator. It is found that, in a weakly doped band insulator, spin fluctuation remains and the spin-singlet d-wave SC state is realized. Present results support an unconventional spin-singlet SC state suggested by the experimental observations in layered nitrides.
Keywords
Cite
@article{arxiv.1210.1324,
title = {Band and Mott Insulators and Superconductivity in Honeycomb-Lattice Ionic-Hubbard Model},
author = {Tsutomu Watanabe and Sumio Ishihara},
journal= {arXiv preprint arXiv:1210.1324},
year = {2015}
}
Comments
8 pages, 9 figures