We present a theoretical study of the dynamics of a tip scanning a graphite surface as a function of the applied load. From the analysis of the lateral forces, we extract the friction force and the corrugation of the effective tip-surface interaction potential. We find both the friction force and potential amplitude to have a power law dependence on applied load with exponent ∼1.6. We interpret these results as characteristic of sharp undeformable tips in contrast to the case of macroscopic and elastic microscopic contacts.
@article{arxiv.cond-mat/0404044,
title = {Power law load dependence of atomic friction},
author = {C. Fusco and A. Fasolino},
journal= {arXiv preprint arXiv:cond-mat/0404044},
year = {2009}
}