Thermal activation in atomic friction: revisiting the theoretical analysis

Area of Science:

• Condensed Matter Physics
• Tribology
• Surface Science

Background:

• Atomic-scale friction is crucial in nanotechnology and is often modeled using the Prandtl-Tomlinson framework.
• Accurate modeling requires precise parameters for corrugation potential (β) and transition attempt frequency (f(0)).

Purpose of the Study:

• To address inaccuracies in the Prandtl-Tomlinson model arising from simplified parameter assumptions.
• To develop a more accurate and generally applicable model for thermal activation effects on atomic-scale friction.

Main Methods:

• Investigated the impact of sinusoidal corrugation potential on friction parameter β.
• Applied harmonic transition state theory to derive a variable transition attempt frequency.
• Utilized a master equation approach for model validation.

Main Results:

• The commonly used sinusoidal corrugation potential can underestimate friction.
• Transition attempt frequency is not constant but varies with the evolving energy landscape.
• An improved analytical expression for friction, incorporating variable parameters, was developed.

Conclusions:

• The refined Prandtl-Tomlinson model offers enhanced accuracy for atomic-scale friction predictions.
• The study highlights the importance of dynamic parameter adjustments in friction modeling.
• The findings are validated within the model's regime of validity.