Topology and symmetry breaking in ABC trilayer graphene
  The effects of topology and electron-electron interactions on the phase diagram of ABC stacked trilayer graphene (TLG) at the neutrality point are investigated within a weak coupling renormalization group approach. We find that the leading instability of TLG with only a forward scattering density-density interaction is towards a mirror-breaking gapless state. Addition of a small, but finite back scattering favors gapped phases, allowing us to make connections to the existing experiments on TLG. We identify a fundamental symmetry difference between TLG and bilayer graphene (BLG) which is responsible for disfavoring nematic states in TLG under the same conditions that favor nematic states in BLG. 
Vladimir Cvetkovic, Oskar Vafek
cond-mat.str-el cond-mat.mes-hall