Superconductivity in Ca-intercalated bilayer graphene

I. I. Mazin; A. V. Balatsky

paper

Superconductivity in Ca-intercalated bilayer graphene

arXiv:0803.3765

Abstract

Recent observation of proximity effect \cite{Morpurgo:2007} has ignited interest in superconductivity in graphene and its derivatives. We consider Ca-intercalated graphene bilayer and argue that it is a superconductor, and likely with a sizeable $T_{c}$ . We find substantial and suggestive similarities between Ca-intercalated bilayer (C $_{6}$ CaC $_{6}$ ), and CaC $_{6}$ , an established superconductor with $T_{c}$ = 11.5 K. In particular, the nearly free electron band, proven to be instrumental for superconductivity in intercalated graphites, does cross the chemical potential in (C $_{6}$ CaC), despite the twice smaller doping level, satisfying the so-called \textquotedblleft Cambridge criterion\textquotedblright . Calculated properties of zone-center phonons are very similar to those of CaC This suggests that the critical temperature would probably be on the same scale as in CaC $_{6}$ .

4 pages latex with 6 ps/eps figure files