Intracellular charge density texture in twisted bilayer graphene away from the chiral limit

The continuum model of twisted bilayer graphene is known to possess perfectly flat, analytically solvable zero modes in the chiral limit, i.e. when electron hopping at AA stacking sites is set to vanish. We previously found that these flat bands yield intra-cellular textures in charge density that possess more nodes at higher magic angles. In particular, we note that there are nodes with real space positions dependent on Bloch momentum, and we now show that this explains the existence of a node on the AA stacking site at the Γ point for the first magic angle, which may have implications for scanning tunnelling microscopy experiments. We also present how these electron density patterns change when tuned away from magic angles and the chiral approximation, as these nodes are no longer protected as features of the exact zero mode wave functions.