Competing many-body instabilities and unconventional superconductivity in graphene

By M. Kiesel, C. Platt, W. Hanke, D. Abanin, R. Thomale. 2011

187 citations recorded by the source corpus.

The band structure of graphene exhibits van Hove singularities (VHSs) at dopings $x=\ifmmode\pm\else\textpm\fi{}1/8$ away from the Dirac point. Near the VHS, interactions effects, enhanced due to the large density of states, can give rise to various many-body phases. We study the competition between many-body instabilities in graphene using the functional renormalization group. We predict a rich phase diagram, which, depending on band structure as well as the range and scale of Coulomb interactions, contains a $d+id$-wave superconducting (SC) phase, or a spin-density-wave phase at the VHS. The $d+id$ state is expected to exhibit quantized charge and spin Hall response, as well as Majorana modes bound to vortices. Nearby the VHS, we find singlet $d+id$-wave and triplet $f$-wave SC phases.

Subfields: Atomic and Molecular Physics, and Optics, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/38a139274d4a1d521049b8ca99a00b85b2fa3e88