Many-body van der Waals interactions in multilayer structures studied by atomic force microscopy

Area of Science:

• Condensed Matter Physics
• Materials Science
• Surface Science

Background:

• Van der Waals interactions in multilayer systems were theoretically predicted to exhibit many-body character.
• Experimental verification has been hindered by the diminishing interaction across intermediate layers.

Purpose of the Study:

• To experimentally verify the many-body nature of van der Waals interactions.
• To investigate the substrate contribution to adhesion at the nanoscale using graphene as a model system.

Main Methods:

• Utilizing atomic force microscopy (AFM) to probe adhesion between a tip and graphene supported on a substrate.
• Comparing experimental results with pairwise dispersion theory and many-body dispersion theory.

Main Results:

• Pairwise dispersion theory overestimates substrate contribution to adhesion.
• Many-body dispersion theory accurately describes the non-additive nature of substrate contributions.
• The many-body effect was further elucidated by analyzing the energy spectrum of charge density fluctuations.

Conclusions:

• The study experimentally confirms the many-body character of van der Waals interactions in layered materials.
• Findings demonstrate the importance of non-additive effects in nanoscale adhesion.
• This work enables modulation of van der Waals forces on 2D material surfaces for technological applications.