▎ 摘 要
The low-energy theory of graphene exhibits spontaneous chiral symmetry breaking due to pairing of quasiparticles and holes, corresponding to a semimetal-insulator transition at strong Coulomb coupling. We report a lattice Monte Carlo study of the critical exponents of this transition as a function of the number of Dirac flavors N-f, finding delta=1.25 +/- 0.05 for N-f=0, delta=2.26 +/- 0.06 for N-f=2 and delta=2.62 +/- 0.11 for N-f=4, with gamma similar or equal to 1 throughout. We compare our results with recent analytical work for graphene and closely related systems and discuss scenarios for the fate of the chiral transition at finite temperature and carrier density, an issue of relevance for upcoming experiments with suspended graphene samples.