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O: Fachverband Oberflächenphysik
O 77: Gerhard Ertl Young Investigator Award Competition
O 77.1: Vortrag
Donnerstag, 21. März 2024, 10:30–11:00, HE 101
Atomic-scale insights into frictional energy dissipation mechanisms during single-molecule manipulation — •Lukas Hörmann1, Alfred J. Weymouth2, and Reinhard J. Maurer1 — 1University of Warwick, Coventry, UK — 2University of Regensburg, Regensburg, Germany
Friction causes significant energy loss in any moving mechanical device. As the miniaturisation of devices reaches the quantum limit, so do dynamical dissipation processes. Fundamentally quantum mechanical mechanisms govern friction at the nanoscale. We account for all relevant quantum mechanical effects, such as charge transfer, or van der Waals interactions, by employing density functional theory, and machine learning and use the probe particle model to simulate energy dissipation. Using this approach, we investigate dynamic friction at the natural limit of a singular atom moving a single chemical bond. This enables us to explore how the local bonding environment of the underlying sample surface affects the energy dissipation that a probe particle experiences. Focussing on the example of a CO-functionalised lateral force microscope that measures frictional energy dissipation above various organic adlayers on Cu(111), we find strong correlations between the local bonding environment and the energy dissipation. Our findings capture the qualitative trends found in experiment. Finally, we present a mechanistic interpretation of our findings that provides insights into the underlying physics of atomic/lateral force microscopy measurements.
Keywords: atom-scale friction; local bonding environment; density functional theory