Extended Data Fig. 1: Bias-dependent contrast maps in NbSe2.
From: Observation of an obstructed atomic band in a transition metal dichalcogenide
(a) shows a large-bias-range differential conductance (\(\frac{dI}{dV}\)) curve for monolayer NbSe2 consistent with previously reported results32,35. The edges of the quasi-flat OA band are delimited by the V1 and C1 peaks, while the band edges of the lower valence bands of NbSe2 are labeled by V2 and V3. The inset shows a zoom-in \(\frac{dI}{dV}\) curve with higher resolution acquired near the V1 region. The spatially-resolved constant-height conductance maps at two bias voltages are illustrated in (b). (c) plots the spatially-averaged conductance at the three C3z-symmetric sites (colored dots) for various bias voltages acquired in two different experiments. The error bars quantify the spreads of the relative conductance values and are computed as explained in the Methods. The conductance is compared with the ab initio spectral function \({\mathcal{A}}(\bf{r},\omega )\) computed at the same C3z-symmetric positions for two different tip heights (z/Å = 4.4, 5.3). The conductance (spectral function) is normalized to one at the 1a site. Stabilization parameters set: (a) Vs = − 2 V, It = 0.8 nA, Vac = 3.5 mV. (b) Vs = − 2 V, It = 2 nA.
