Fig. 5: Landauer–Büttiker multi-terminal simulation of chiral edge transport with edge–bulk scattering.
From: Direct observation of chiral edge current at zero magnetic field in a magnetic topological insulator
a Setup for measuring \({V}_{{{\rm{BH}}}}/{I}_{{{\rm{BH}}}}\) using electrodes B and H on the 7-SL with all the other electrodes grounded. b The voltage drop and the current between electrodes B and H as a function of \({V}_{{{\rm{g}}}}\) under the configuration shown in (a). At the CNP, \({I}_{{{\rm{BH}}}}\) is suppressed but \({V}_{{{\rm{BH}}}}\) peaks, suggesting enhanced edge–bulk scattering. c Illustration of the edge–bulk scattering at the CNP. Puddles of chemical potential inhomogeneity (dashed circles) act as bulk scattering centers for chiral edge current carriers (orange balls). CES: chiral edge state. d Schematics to simulate chiral edge transport between two electrodes with finite bulk–edge scattering. The bulk–edge scattering is taken into account by inserting various numbers of virtual electrodes (N = 2, 4, 8, and 12). e Simulated gate dependence \({\rho }_{{xx}}\) as a function of \({V}_{{{\rm{g}}}}\) under different N. \({\rho }_{{xx}}\) increases with increasing N at CNP, which suggests enhanced dissipation of chiral edge transport due to scattering with the bulk. N = 12 (orange circles) overlaps with experimental \({\rho }_{{xx}}\) data at zero field (orange line). f Gate dependence of simulated \({\rho }_{{yx}}\) for N = 12 (black squares) and experimental \({\rho }_{{yx}}\) data at zero field (blue line), which suggests that the edge–bulk scattering suppresses the quantization of Hall resistance of QAH.
