Extended Data Fig. 1: Sensing and tuning edge potential.
From: Visualizing interaction-driven restructuring of quantum Hall edge states
a, Schematic illustration of the working principle of STS potential sensing. When graphene is highly incompressible (e.g. v = 2), variation in local potential φ as felt by graphene (blue) shifts the energy of LLs (red), the latter of which is measured by the VB at which resonant tunneling to LLs occurs, i.e. peak in dI/dV(VB). b, STS measured along a linear trajectory across the gate-defined edge with νB = νP = 2. VPG and VBG are adjusted within the gap to balance ϕ in the PG- and BG- controlled bulk to extract the intrinsic potential variations. c,d, ϕ extracted from the STS mapping near a flipped L-shaped edge of PG (same as Fig. 1b) with νB = νP = 2, where VPG and VBG are adjusted within the gap to balance (c) or offset (d) φ across the edge. b is taken at y = 300 nm in c,d. Yellow line overlaid on the x-axis in b denotes the spatial extent of the scanned area in c,d.
