Quantifying the fragility of unprotected quadratic band crossing points

@article{Hesselmann2019QuantifyingTF,
  title={Quantifying the fragility of unprotected quadratic band crossing points},
  author={S Hesselmann and Carsten Honerkamp and Stefan Wessel and Thomas C. Lang},
  journal={Physical Review B},
  year={2019}
}
We examine a basic lattice model of interacting fermions that exhibits quadratic band crossing points (QBCPs) in the non-interacting limit. In particular, we consider spinless fermions on the honeycomb lattice with nearest neighbor hopping $t$ and third-nearest neighbor hopping $t''$, which exhibits fine-tuned QBCPs at the corners of the Brillouin zone for ${t'' = t/2}$. In this situation, the density of states remains finite at the Fermi level of the half-filled band and repulsive nearest… 

Gross-Neveu-Heisenberg criticality from competing nematic and antiferromagnetic orders in bilayer graphene

We study the phase diagram of an effective model of competing nematic and antiferromagnetic orders of interacting electrons on the Bernal-stacked honeycomb bilayer, as relevant for bilayer graphene.

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