▎ 摘　　要

An armchair graphene nanoribbon switch has been designed based on the principle of the Klein paradox. The resulting switch displays an excellent on-off ratio performance. An anomalous tunneling phenomenon, in which electrons do not pass through the graphene nanoribbon junction even when the conventional resonance condition is satisfied, is observed in our numerical simulations. A selective tunneling rule is proposed to explain this interesting transport behavior based on our analytical results. Based on this selective rule, our switch design can also achieve the confinement of an electron to form a quantum qubit.