Figure 3 : Resistivity dipoles around nanoscale voids.

From: Electrical resistance of individual defects at a topological insulator surface

Figure 3

(a) STM image of a typical void in the sample surface. Scale bar, 5 nm. (b) Corresponding potential map showing a dipole shaped feature centred at the defect. The lobes of the dipole are aligned with the macroscopic current direction. (c) Resistor network model mask with indicated schematic of the resistors. (d) Calculated potential distribution around the defect resulting from the resistor network model shown in c, after background subtraction. (e) Sections indicated in ad. Solid black line: experimental height profile section from a. Solid red line: experimental potential section from b. Dashed black line: section of the model system shown in c. Dotted blue line: calculated potential section from d.