Atomistic mechanisms for frictional energy dissipation during continuous sliding

Area of Science:

• Physics
• Materials Science
• Tribology

Background:

• Sliding friction's energy dissipation mechanisms remain poorly understood despite extensive research.
• A fundamental understanding is lacking even for simple systems like a rigid slider on a periodic surface.

Purpose of the Study:

• To establish the atomistic mechanisms of frictional energy dissipation.
• To analyze a rigid object moving continuously on a solid surface with vibrational degrees of freedom.

Main Methods:

• First-principles-based analysis.
• Investigating a dynamic system with independent, non-interacting phonon modes.

Main Results:

• Identified two primary energy dissipation mechanisms: pumping energy into resonant modes and destructive interference of phonon mode contributions.
• Demonstrated that these mechanisms cause irreversibility via 'dynamical stochastization'.
• Showed that mechanical energy transformation into heat plays a minor role in friction.

Conclusions:

• Friction's microscopic mechanisms are clarified through dynamical stochastization and phonon interference.
• Insights pave the way for direct control over friction.
• Challenges conventional views on the role of heat in friction.