Strained graphene in the quantum Hall regime*

The coupling between electronic and mechanical properties in 2D materials has become an important tool to control their properties. In this route, graphene nanoribbons with longitudinal deformations have been proposed as electronic waveguides for valley polarized currents [1]. As strained-folds can be easily engineered on graphene samples [2], we propose a theoretical study of the strain effects on a graphene membrane in the quantum Hall regime. A continuum model description allows to obtain analytic expressions for corrections to the Landau levels while a numerical tight-binding band structure calculation confirms these results. Using recursive Green’s function method, we obtain new extra conducting channels due to the "new edges” formed at the fold. We discuss the magnetic field effect on the system that protects these extra channels against edge disorder. Our results are consistent with recent experimental measurements [3]. [1] R. Carrillo-Bastos et al., PRB 94, 125422 (2016). [2] Y. Jiang et al., Nano Lett. 17, 2839 (2017). [3] See abstract: Valley-selective Channels in Strained Graphene Wrinkles, by the group of Eva Andrey.