Stochastic analysis of movements on surfaces: The case of C60on Au(1 1 1)

Molecular dynamics simulations of C<inf>60</inf>on Au(1 1 1) reveal that the molecular diffusion consists of randomsequences of stick, slide, and stick and slip periods. Stochastic analysis of forty trajectories shows thatinitially C<inf>60</inf> follows a super-diffusive-sub-ballistic-like motion, which then turns into super-diffusive.Individual trajectories present a variety of diffusive motions that even include subdiffusion. The analysisof the displacement moments indicates Fractional Brownian motion (FBM), as underlying stochastic-mechanism, a finding further supported by the analysis of the velocity correlation function.