Chiral superconductivity from repulsive interactions in doped graphene
Abstract
We identify graphene as a system where chiral superconductivity can be realized. Chiral superconductivity involves a pairing gap that winds in phase around the Fermi surface, breaking time reversal symmetry. We consider a unique situation arising in graphene at a specific level of doping, where the density of states is singular, strongly enhancing the critical temperature T_c. At this doping level, the Fermi surface is nested, allowing superconductivity to emerge from repulsive electron-electron interactions. We show using a renormalization group method that superconductivity dominates over all competing orders for any choice of weak repulsive interactions. Superconductivity develops in a doubly degenerate, spin singlet channel, and a mean field calculation indicates that the superconductivity is of a chiral d+id type. We therefore predict that doped graphene can provide experimental realization of spin-singlet chiral superconductivity.
Cite
@article{arxiv.1107.1903,
title = {Chiral superconductivity from repulsive interactions in doped graphene},
author = {Rahul Nandkishore and Leonid Levitov and Andrey Chubukov},
journal= {arXiv preprint arXiv:1107.1903},
year = {2015}
}