Fig. 1: Surface defects and electronic spectrum of MBST.
From: Anti-site defect-induced disorder in compensated topological magnet MnBi2-xSbxTe4
a, b STM images showing intrinsic defects in large-scale and atomic resolution scans. c Atomic models of typical intrinsic defects in MBST viewed from the top (top panel) and side (bottom panel). d Typical tunnelling spectrum of MBST averaged over an area of 50 × 50 nm2, plotted on a logarithmic scale, as well as a linear scale (upper inset). The flat region in the inset corresponds to the bulk band gap. In the log-scale plot, the surface state inside the bulk band gap is evident and shows another gap - the surface state exchange gap. A corresponding band schematic is shown as the left inset. We estimate the bulk band gap (\(\approx 200\,{{{{{\rm{meV}}}}}}\)) and surface state exchange gap (\(2\Delta \approx 56\,{{{{{\rm{meV}}}}}}\)) from linear extrapolation of the band edges (black and red dashed lines, respectively) to the measurement noise level (horizontal dotted line), similar to Refs. 33,47.
