Atomic and electronic reconstruction at van der Waals interface in twisted bilayer graphene

Understand

Control of the interlayer twist angle in two-dimensional (2D) van der Waals (vdW) heterostructures enables one to engineer a quasiperiodic moir\'e superlattice of tunable length scale.

• In twisted bilayer graphene (TBG), the simple moir\'e superlattice band description suggests that the electronic band width can be tuned to be comparable to the vdW interlayer interaction at a 'magic angle', exhibiting strongly correlated behavior.
• However, the vdW interlayer interaction can also cause significant structural reconstruction at the interface by favoring interlayer commensurability, which competes with the intralayer lattice distortion.
• Here we report the atomic scale reconstruction in TBG and its effect on the electronic structure.