Moving breather collisions in Klein-Gordon chains of oscillators
Grupo de Física No Lineal, Área de Física
Teórica, Facultad de Física, Universidad de Sevilla, Avda.
Reina Mercedes, s/n, 41012 Sevilla, Spain
2 Grupo de Física No Lineal, Departamento de Fisica Aplicada I, ETSI Informática, Universidad de Sevilla, Avda. Reina Mercedes, s/n, 41012 Sevilla, Spain
Corresponding author: a firstname.lastname@example.org
Revised: 5 June 2009
Published online: 21 July 2009
We investigate the collisions of moving breathers, with the same frequency, in three different Klein-Gordon chains of oscillators. The on-site potentials are: the asymmetric and soft Morse potential, the symmetric and soft sine-Gordon potential and the symmetric and hard φ4 potential. The simulation of a collision begins generating two identical moving breathers traveling with opposite velocities, they are obtained after perturbing two identical stationary breathers which centers are separated by a fixed number of particles. If this number is odd we obtain an on-site collision, but if this number is even we obtain an inter-site collision. Apart from this distinction, we have considered symmetric collisions, if the colliding moving breathers are vibrating in phase, and anti-symmetric collisions, if the colliding moving breathers are vibrating in anti-phase. The simulations show that the collision properties of the three chains are different. The main observed phenomena are: breather generation with trapping, with the appearance of two new moving breathers with opposite velocities, and a stationary breather trapped at the collision region; breather generation without trapping, with the appearance of new moving breathers with opposite velocities; breather trapping at the collision region, without the appearance of new moving breathers; and breather reflection. For each Klein-Gordon chain, the collision outcomes depend on the lattice parameters, the frequency of the perturbed stationary breathers, the internal structure of the moving breathers and the number of particles that initially separates the stationary breathers when they are perturbed.
PACS: 05.45.Yv – Solitons / 63.20.Pw – Localized modes / 63.20.Ry – Anharmonic lattice modes / 66.30.hp – Molecular crystals
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2009