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arXiv · 1210.7595

High-temperature surface superconductivity in rhombohedral graphite

N. B. Kopnin·M. Ijäs·A. Harju·T. T. Heikkilä
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Abstract

Surface superconductivity in rhombohedral graphite is a robust phenomenon which can exist even when higher order hoppings between the layers lift the topological protection of the surface flat band and introduce a quadratic dispersion of electrons with a heavy effective mass. We show that for weak pairing interaction, the flat band character of the surface superconductivity transforms into a BCS-like relation with high critical temperature characterized by a higher coupling constant due to a much larger density of states than in the bulk. Our results offer an explanation for the recent findings of graphite superconductivity with an unusually high transition temperature.

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N. B. Kopnin, M. Ijäs, A. Harju, T. T. Heikkilä. 2012-10-29. High-temperature surface superconductivity in rhombohedral graphite. https://doi.org/10.1103/physrevb.87.140503

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