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arXiv · 1207.5802

Interplay of superconductivity and spin density wave order in doped graphene

Rahul Nandkishore·Andrey V. Chubukov
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Abstract

We study the interplay between superconductivity and spin density wave order in graphene doped to 3/8 or 5/8 filling (a Van Hove doping). At this doping level, the system is known to exhibit weak coupling instabilities to both chiral d + id superconductivity and to a uniaxial spin density wave. Right at van Hove doping, the superconducting instability is strongest and emerges at the highest Tc, but slightly away from van-Hove doping a spin-density-wave likely emerges first. We investigate whether at some lower temperature superconductivity and spin-density-waves co-exist. We derive the Landau-Ginzburg functional describing interplay of the two order parameters. Our calculations show that superconductivity and spin density wave order do not co-exist and are separated by first-order transitions, either as a function of doping or as a function of T.

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Rahul Nandkishore, Andrey V. Chubukov. 2012-07-24. Interplay of superconductivity and spin density wave order in doped graphene. https://doi.org/10.1103/physrevb.86.115426

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