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Charge order and superconductivity in a two-dimensional triangular lattice at n=2/3

Hiroshi Watanabe·Masao Ogata
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Abstract

To investigate the possibility of charge order and superconductivity in a doped two-dimensional triangular lattice, we study the extended Hubbard model with variational Monte Carlo method. At n=2/3, a commensurate filling for a triangular lattice, it is shown that the nearest-neighbor Coulomb interaction V induces honeycomb-type charge order and antiferromagnetic spin order at U>10t. We also discuss the possibility of superconductivity induced by charge fluctuation and the relation to the superconductivity in Na_{0.35}CoO_{2}1.3H_{2}O and theta-type organic condoctors.

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Hiroshi Watanabe, Masao Ogata. 2005-07-19. Charge order and superconductivity in a two-dimensional triangular lattice at n=2/3. https://doi.org/10.1143/jpsj.74.2901

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