Tuning Electronic Friction in Structural Superlubric Schottky Junctions.

Area of Science:

• Tribology
• Materials Science
• Condensed Matter Physics

Background:

• Friction dissipation occurs through various channels like phononic and electronic excitation, often entangled and difficult to control.
• Structural superlubricity (SSL) offers a wear-free state with ultralow friction, but electronic friction remains a challenge.
• Controlling electronic friction is crucial for advanced tribological applications.

Purpose of the Study:

• To investigate and control electronic friction in the structural superlubricity (SSL) state.
• To achieve wide-range, continuous, and reversible tuning of electronic friction.
• To elucidate the mechanism behind electronic friction in a Schottky junction.

Main Methods:

• Constructed a Schottky junction between a microscale graphite flake and a doped silicon substrate in the SSL state.
• Tuned electronic friction by varying the bias voltage across the junction.
• Employed perturbative finite element analysis to understand the friction mechanism.

Main Results:

• Achieved a 6x wide-range, continuous, and reversible tuning of electronic friction.
• Observed no wear or oxidation at the sliding interfaces, confirming the SSL state.
• Ultralow friction coefficients indicated that electronic friction was the dominant factor in tuning.

Conclusions:

• Electronic friction in SSL can be effectively tuned using a Schottky junction and bias voltage.
• The study demonstrates a novel approach to control friction by manipulating charge carrier dynamics.
• The findings pave the way for advanced friction management in nanoscale devices and systems.