Nonlinear dynamics of dimers on periodic substrates
Department of Theoretical Physics, University of Nijmegen,
Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
Corresponding author: a email@example.com.
Revised: 15 November 2002
Published online: 27 January 2003
We study the dynamics of a dimer moving on a periodic one-dimensional substrate as a function of the initial kinetic energy at zero temperature. The aim is to describe, in a simplified picture, the microscopic dynamics of diatomic molecules on periodic surfaces, which is of importance for thin film formation and crystal growth. We find a complex behaviour, characterized by a variety of dynamical regimes, namely oscillatory, “quasi-diffusive” (chaotic) and drift motion. Parametrically resonant excitations of internal vibrations can be induced both by oscillatory and drift motion of the centre of mass. For weakly bound dimers a chaotic regime is found for a whole range of velocities between two non-chaotic phases at low and high kinetic energy. The chaotic features have been monitored by studying the Lyapunov exponents and the power spectra. Moreover, for a short-range interaction, the dimer can dissociate due to the parametric excitation of the internal motion.
PACS: 68.35.Ja – Surface and interface dynamics and vibrations / 05.45.-a – Nonlinear dynamics and nonlinear dynamical systems / 47.52.+j – Chaos
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2003