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