Propagating edge states in strained graphene

Published in Physical Review B, 2017

Grazia Salerno, Tomoki Ozawa, Hannah M. Price, and Iacopo Carusotto
Phys. Rev. B 95, 245418 (2017)

We investigate the helically propagating edge states associated with pseudo-Landau levels in strained honeycomb lattices. We exploit chiral symmetry to derive a general criterion for the existence of these propagating edge states in the presence of only nearest-neighbor hoppings and we verify our criterion using numerical simulations of both uniaxially and trigonally strained honeycomb lattices. We show that the propagation of the helical edge state can be controlled by engineering the shape of the edges. Sensitivity to chiral-symmetry-breaking next-nearest-neighbor hoppings is assessed. Our result opens up an avenue toward the precise control of edge modes through manipulation of the edge shape.