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

Area of Science:

• Surface science
• Condensed matter physics
• Nanoscale science

Background:

• Local electrostatic fields are crucial in nanoscale systems, impacting catalysis, nanoelectronics, and quantum nanoscience.
• Surface-averaging techniques offer limited insight into these potentials, which depend on nanostructure geometry, material, and environment.

Purpose of the Study:

• To image and quantify electrostatic potentials and surface dipole moments of silver and gold nanostructures.
• To establish an experimental benchmark for theoretical calculations of nanoscale electrostatic properties.
• To analyze the mechanisms of dipole formation and their dependence on atomic and structural factors.

Main Methods:

• Experimental imaging of electrostatic potential over adatoms, chains, and clusters of Ag and Au on Ag(111).
• Quantification of surface dipole moments based on total charge density.
• Density functional theory (DFT) calculations for comparison and deeper analysis.

Main Results:

• Successful imaging of electrostatic potentials on assembled Ag and Au nanostructures.
• Quantification of surface dipole moments, establishing a benchmark for theoretical models.
• DFT calculations showed excellent agreement with experimental data.
• Analysis revealed key mechanisms of dipole formation influenced by atomic properties and nanostructure shape.

Conclusions:

• The study provides a detailed understanding of electrostatic potential and dipole formation in noble metal nanostructures.
• Experimental data and theoretical calculations establish a benchmark for nanoscale electrostatic studies.
• Insights gained can guide the design of advanced nanoscale systems, including single-atom catalysts.