s$_\pm$ pairing near a Lifshitz transition

Vivek Mishra; Douglas J. Scalapino; Thomas A. Maier

doi:10.1038/srep32078

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arXiv · 1603.03756

s$_\pm$ pairing near a Lifshitz transition

Vivek Mishra·Douglas J. Scalapino·Thomas A. Maier

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Abstract

Observation of robust superconductivity in some of the iron based superconductors in the vicinity of a Lifshitz point where a spin density wave instability is suppressed as the {hole} band drops below the Fermi energy raise questions for spin-fluctuation theories. Here we discuss spin-fluctuation pairing for a bilayer Hubbard model, which goes through such a Lifshitz transition. We find s$_\pm$ pairing with a transition temperature that peaks beyond the Lifshitz point and a gap function that has essentially the same magnitude but opposite sign on the incipient hole band as it does on the electron band that has a Fermi surface.

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Vivek Mishra, Douglas J. Scalapino, Thomas A. Maier. 2016-03-11. s$_\pm$ pairing near a Lifshitz transition. https://doi.org/10.1038/srep32078

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