Figure 4: Spatially resolved tunnelling spectra.
From: Mapping polarization induced surface band bending on the Rashba semiconductor BiTeI
(a) STM topography showing the boundary between areas of I (left) and Te (right) terminated surface (Vbias=0.7 V, Iset=0.3 nA). Scale bar, 20 nm. (b) Spatially resolved STS measurements (averaged over the short axis of the topography image). Though the starting set-point chosen here (Vbias=1.5 V, Iset=0.3 nA) yields curves less representative of the DOS than those shown in Fig. 3 (with a set-point at Vbias=0.7 V, Iset=0.3 nA), this set-point is chosen to attain approximate parity in signal intensity between curves taken from each termination, with an emphasis on resolving the lateral behaviour at the junction. Vertical dashed lines enclose the transition region between the characteristic electronic structures of the two terminations.
