Effect of anisotropy on phase transitions in graphene

Phase transitions in anisotropic graphene

“…In a previous paper 6 we used a 1-loop result for the photon polarization, instead of solving the coupled self-consistent equation (18). This approximation is based on the fact that the the fermion density of states vanishes at the Dirac points, and is widely adopted because of the significant numerical advantages.…”

“…The effect of these approximations is, however, difficult to predict, and different approximations have led to different predictions about the direction that the critical coupling in an anisotropic system moves, relative to the isotropic one. In a previous paper, 6 we have presented results obtained numerically from a coupled set of Schwinger-Dyson (SD) equations using only two approximations: we truncated the hierarchy of SD integral equations using a common vertex ansatz (which will be discussed below), and we used a 1-loop approximation for the photon polarization tensor. In this paper, we relax the second of these approximations.…”

Non-perturbative field theoretical aspects of graphene and related systems

“…Effects of anisotropy (strain) in the gap equation have been recently considered in Ref. [38]. By writing the fermion propagator of RQED with strain as…”

“…Including one-loop vacuum polarization effects and a suitable generalization of the Ball-Chiu vertex, the authors of Ref. [38] solved the gap equation and searched for the effect of η on the critical coupling. They observe that the net effect is to increase the value of α c for chiral symmetry breaking.…”

“…In Ref. [38], anisotropy associated to strained graphene was shown to slightly affect the critical coupling. Moreover, in Ref.…”