Field-induced Energy Gaps in Bilayer Graphene under Shear*

Using the first-principles calculations method, we study the effects of shear on field-induced insulating states of bilayer graphene (BLG). It is shown that the low energy bands near the charge neutral point of BLG change significantly upon application of shear. We also find that the energy gap of BLG under transverse electric field sensitively depend on both direction and amount of shear. Generally, the field-induced energy gap decreases as the sliding increases under shear. For BLG with the specific direction of shear, the shear can quench the energy gap to zero completely even in the presence of electric field thus realizing insulator-to-metal transition just by sliding. We discuss origins of these interesting phenomena and suggest some experimental methods to detect the transition.