Visualizing mesoscopic electronic structure of twisted graphene heterostructures

The moiré spatial structure of twisted graphene heterostructures gives rise to a myriad of electronic properties. The mini bands arising from the moiré potential stabilize many nearby electronic phases accessible through carrier density, displacement field, and magnetic field. By adjusting the twist angle, a variety of structural motifs are also accessible. At low twist angles, structural reconstruction produces a periodic pattern of more uniform stackings separated by domain walls, making the moiré one route to stabilizing relatively large areas of rhombohedral graphene whose flat bands give rise to correlated physics and diverse electronic phases, e.g. [1-5]. Here we use low temperature conductive atomic force microscopy to image the electronic structure arising both within and at the boundary between mesoscale patches of rhombohedral and Bernal stacking in twisted graphene heterostructures. Furthermore, we investigate the interplay of this inhomogeneous electronic landscape with the formation of Landau levels under magnetic field.

 

[1] Kerelsky Proc Natl Acad Sci 118 e2017366118 (2021)

[2] Shi Nature 584, 210 (2020)

[3] Zhou Nature 598, 429 (2021)

[4] Zhou Science 375, 774 (2022)

[5] Han arXiv:2305.03151 (2023)