[2210.01831] Mapping quantum Hall edge states in graphene by scanning tunneling microscopy

[Submitted on 4 Oct 2022]

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Overview: The quantum Hall edge state is a classic example of the bulk boundary correspondence. They tend to have complex reconstructions that require detailed investigation at high spatial resolution. Here we use scanning tunneling microscopy to map quantum Hall edge states in monolayer graphene at a magnetic field of 7 T. The graphene samples feature gate-tunable lateral interfaces between regions with different filling fractions. We compare this result with detailed tight-binding calculations that quantitatively account for tip-induced QD-induced perturbations. It can be seen that the edge state pattern is mapped with little perturbation by appropriately choosing the gate voltages. We observe extended compressive regions, edge-state antinode structures, and meandering along the lateral interface.