https://doi.org/10.1140/epjb/e2016-70225-1
Regular Article
Chaotic delocalization of two interacting particles in the classical Harper model
Laboratoire de Physique Théorique du CNRS, IRSAMC, Université de
Toulouse, CNRS, UPS, 31062
Toulouse,
France
a
e-mail: dima@irsamc.ups-tlse.fr
Received: 12 April 2016
Received in final form: 13 May 2016
Published online: 20 June 2016
We study the problem of two interacting particles in the classical Harper model in the regime when one-particle motion is absolutely bounded inside one cell of periodic potential. The interaction between particles breaks integrability of classical motion leading to emergence of Hamiltonian dynamical chaos. At moderate interactions and certain energies above the mobility edge this chaos leads to a chaotic propulsion of two particles with their diffusive spreading over the whole space both in one and two dimensions. At the same time the distance between particles remains bounded by one or two periodic cells demonstrating appearance of new composite quasi-particles called chaons. The effect of chaotic delocalization of chaons is shown to be rather general being present for Coulomb and short range interactions. It is argued that such delocalized chaons can be observed in experiments with cold atoms and ions in optical lattices.
Key words: Statistical and Nonlinear Physics
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2016