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arXiv · 1101.4462

Theory for superconductivity in (Tl,K)Fe$_x$Se$_2$ as a doped Mott insulator

Yi Zhou·Dong-Hui Xu·Fu-Chun Zhang·Wei-Qiang Chen
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Abstract

Possible superconductivity in recently discovered (Tl,K)Fe$_x$Se$_2$ compounds is studied from the viewpoint of doped Mott insulator. The Mott insulating phase is examined to be preferred in the parent compound at $x=1.5$ due to the presence of Fe vacancies. Partial filling of vacancies at the Fe-sites introduces electron carriers and leads to electron doped superconductivity. By using a two-orbital Hubbard model in the strong coupling limit, we find that the s-wave pairing is more favorable at small Hund's coupling, and d$_{x^2-y^2}$ wave pairing is more favorable at large Hund's coupling.

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Yi Zhou, Dong-Hui Xu, Fu-Chun Zhang, Wei-Qiang Chen. 2011-05-23. Theory for superconductivity in (Tl,K)Fe$_x$Se$_2$ as a doped Mott insulator. https://doi.org/10.1209/0295-5075%2F95%2F17003

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