Lane formation in binary complex plasmas: Role of non-additive interactions and initial configurations

Max Planck Institute for Extraterrestrial Physics - 85741 Garching, Germany, EU

^a jiang@mpe.mpg.de

Received: 27 September 2010
Accepted: 30 November 2010

Abstract

In this letter, we study the influence of non-additive interactions on lane formation, using Langevin dynamics simulations. Lane formation and positive non-additivity have recently been observed in binary complex plasmas on board the International Space Station (ISS). Positive non-additivity of particle interactions is known to stimulate phase separation (demixing), but its effect on lane formation is unknown. We show that there is a non-additivity–stimulated crossover from the normal laning mode to a demixing-dominated laning mode. To analyze this crossover on the individual particle level we applied a very sensitive order parameter for lane formation based on anisotropic scaling indices. Extensive numerical simulations enabled us to identify a critical value of the non-additivity parameter Δ for the crossover. In addition the simulations revealed that the dynamics of lane formation is strongly influenced by the exact spatial configurations at the very moment of contact between two different complex plasmas.