A new mechanism for superconductivity in the newly discovered Co-based oxide is proposed by using charge fluctuation. A single-band extended Hubbard model on the triangular lattice is studied within random phase approximation. f-wave triplet superconductivity is stabilized in the vicinity of charge-density-wave instability, which is in sharp contrast with the square-lattice case. The physical origin of the realization of the f-wave triplet state as well as the relevance to experiments are discussed.
@article{arxiv.cond-mat/0311266,
title = {Superconductivity in Na_xCoO_2yH_2O by charge fluctuation},
author = {Yasuhiro Tanaka and Youichi Yanase and Masao Ogata},
journal= {arXiv preprint arXiv:cond-mat/0311266},
year = {2009}
}