Fig. 1: Measurement principle of SQDM. | Nature Communications

Fig. 1: Measurement principle of SQDM.

From: Electrostatic potentials of atomic nanostructures at metal surfaces quantified by scanning quantum dot microscopy

Fig. 1

A single molecule, in this case PTCDA, is attached to the probe tip. It acts as a quantum dot (QD) that can be gated and charged with individual electrons by applying a bias voltage Vb to the sample. To image the electrostatic potential \({V}^{*}\), the probe scans the sample (here, a chain of 8-Ag adatoms on Ag(111)) while changes in the surface potential beneath the tip are compensated by adjusting Vb via a controller C, maintaining a constant QD potential ΦQD.

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