Fig. 3: Backscattering in A-terminated indenene edge states.
From: Backscattering in topological edge states despite time-reversal symmetry
a Indenene edge topography adjacent to H-sat. SiC, acquired at low corrugation settings (IT = 500 pA, Vbias = −1 V). Defects and kinks in the edge (white arrows) indicate scattering centers that separate four segments, with segments 1, 2, and 4 being of flat A type, see Supplementary Discussion I and VII. b Line scan of dI/dV(E, x) taken along the red path in a showing typical QPI-related dI/dV modulations confined to flat edge A segments as well as variations in \({\Delta }_{\sup }\) among them. c Spatially resolved dI/dV(x, y) maps of segment 4 (dashed red rectangle in a) taken at energies E+1 to E−3 (labeled in b) and demonstrating edge localization of the respective dI/dV peaks (red arrows) that are spatially separated by 2π/q (IT = 600 pA, Vbias = −1 V). d Cumulative plot of segment 2 dI/dV(E) curves showing dI/dV peaks E−5 to E+2 as well as an energy region within \({\Delta }_{\sup }\) of QPI suppression. e Separate zoom measurement of dI/dV(E) in segment 2 demonstrating absence of spatial dI/dV-modulation except for a mild ZBA as well as finite differential conductance in \({\Delta }_{\sup }\) (IT = 250 pA, Vbias = 0.1 V). f Inverse length 1/L-dependence of the topmost level spacing \({\Delta }_{\sup }\) and \({\Delta }_{-2}^{-1}\) in a quantum well picture, as indicated in the inset of b. Assuming linear E(q) dependence for these energies, we fit a \(\Delta={\Delta }_{\infty }+\hslash {v}_{{{\rm{F}}}}^{{{\rm{e}}}}\pi /L\) dependence to the data yielding Δ∞ = (0.26 ± 0.06) eV for \({\Delta }_{\sup }\).
