Klein Tunneling and Fabry-Pérot Resonances in Twisted Bilayer Graphene

Abstract: The paper discusses the Klein tunneling and Fabry-P\'erot resonances of charge carriers through a rectangular potential barrier in twisted bilayer graphene. Within the framework of the low-energy excitations, the transmission probability and the conductance are obtained depending on the parameters of the problem. Owing to the different chirality in twisted bilayer graphene, the propagation of charge carriers exhibits an anisotropic behavior in transmission probability and Fabry-P\'erot resonances. Moreover, we show that the anisotropy of the charge carriers induces asymmetry and deflection in the Fabry-P\'erot resonances and Klein tunneling, and they are extremely sensitive to the height of the potential applied. Additionally, we found that the conductance is strongly sensitive to the barrier height but weakly sensitive to the barrier width. Therefore, it is possible to control the maxima and minima of the conductance of charge carriers in twisted bilayer graphene. With our results, we gain an in-depth understanding of tunneling properties in twisted bilayer graphene, which may help in the development and designing of novel electronic nanodevices based on anisotropic 2D materials.