High-voltage differential conductance spectra g ( r , V ) are shown as a solid black curve, whereas the spatially averaged spectrum \(\overline{g\left(V\right)}\) is shown as a dashed curve. The example spectrum is measured at a location (yellow dot) in a . Such high junction resistances of 85 GΩ or large tip sample distances preclude the effects of the tip sample electric field on g ( V ). The separation between the lower and upper bands is clearly visible for the example spectrum (blue arrows) as well as for the average spectrum (red double-headed arrow). Setpoint V S = -600 mV: I S = 7 pA.
