Superlubricity - a new perspective on an established paradigm

TL;DR

This paper introduces a new model based on the registry index concept to explain superlubricity in layered materials, successfully predicting experimental frictional behaviors and extending predictions to other materials like boron nitride.

Contribution

It establishes a direct relation between interlayer commensurability and wearless friction, providing a simple, efficient model that accurately captures experimental results and predicts superlubricity in new materials.

Findings

The model accurately reproduces frictional behavior of graphene on graphite.

Superlubricity is predicted to occur in hexagonal boron nitride.

The approach enables large-scale interface modeling beyond standard methods.

Abstract

Superlubricity is a frictionless tribological state sometimes occurring in nanoscale material junctions. It is often associated with incommensurate surface lattice structures appearing at the interface. Here, by using the recently introduced registry index concept which quantifies the registry mismatch in layered materials, we prove the existence of a direct relation between interlayer commensurability and wearless friction in layered materials. We show that our simple and intuitive model is able to capture, down to fine details, the experimentally measured frictional behavior of a hexagonal graphene flake sliding on-top of the surface of graphite. We further predict that superlubricity is expected to occur in hexagonal boron nitride as well with tribological characteristics very similar to those observed for the graphitic system. The success of our method in predicting experimental results along with its exceptional computational efficiency opens the way for modeling large-scale material interfaces way beyond the reach of standard simulation techniques.