Quasi-localized charge approximation approach for the nonlinear structures in strongly coupled Yukawa systems

Abstract

Strongly coupled systems occupying the transitional range between the Wigner crystal and fluid phases are most dynamic constituents of the nature. Highly localized but strongly interacting elements in this phase posses enough thermal energy to trigger the transition between a variety of short to long range order phases. Nonlinear excitations are often the carriers of proliferating structural modifications in the strongly coupled Yukawa systems. Well represented by a laboratory dusty plasma, these systems show explicit propagation of nonlinear shocks and solitary structures both in experiments and in first principle simulations. The shorter scale length contributions remain absent at strong screening in present approximate models which nevertheless prescribe nonlinear solitary solutions that consequently lose their coherence in a numerical evolution of the system under a special implementation of the quasi-localized charge approximation formulation. The stable coherent structures self-consistently emerge following an initial transient in the numerical evolution which adapts QLCA approach to spatiotemporal domain for accessing the nonlinear excitations in the strong screening limit. The present kappa ~ 1 limit of the existing Yukawa fluid models to show agreement with the experiment and MD simulations has therefore been overcome and the coherent nonlinear excitaitons have become characterizable up to kappa ~ 2.7, before they becoming computationally challenging in present implementation.