Dynamics of Nonlinear Dust Acoustic Waves and Complex Systems(3/3)

This 3-year project continues our series researches on the dynamics of dusty plasmas and complex systems.The dusty plasma composed of negative charged dust particles suspended in a low pressure discharge is a strongly coupled complex system. It can be tuned from the solid to the gas state which supports self-excited dust acoustic waves with longitudinal dust particle oscillation. The capability of monitoring and correlating large area dust densityfluctuation and particle motions makes it a good platform to understand the generic dynamical behaviors of nonlinear density waves in gases and plasmas.In the past three years, we experimentally demonstrated the first observations of singular events such as the low amplitude hole filaments coinciding with defect filaments, the surrounding acoustic vortex pairs with opposite helicities, and the nearby spatio-temporally uncertain rogue wave events in weakly disordered self-excited dust acoustic waves. We constructed Eulerian-Lagrangian picture from the wave-particle interaction view to understand the key origins for the formation of those singular events. Moreover, we experimentally and numerically explored crystallization microdynamics of quenched Yukawa liquids, the seismic like micro-structural rearrangement in weakly sheared ultra-cold dusty plasma liquids, and the dynamics of passive and active rod-like particles such as dense E-Coli suspensions in liquids.In this new project, extending from past researches we will conduct the following researches: a) the spatio-temporal correlation of amplitude hole filaments, rogue waves, and acoustic vortices, b) whether they can be used as fundamental excitations to understand and characterize more disordered 3D nonlinear dust acoustic waves, c) whether they can be found in other simpler weakly disordered density waves in plasmas or gases, d) whether a single stable acoustic vortex can be excited in a small dusty plasma cluster and the angular momentum it carries, e) the mode-mode interaction of dust acoustic wave turbulence, f) the mode-mode coupling of superheated dusty plasma crystal, g) the micro-structure and motion of dense spherocylinders (i.e. rods with two hemispherical ends) around the freezing points under various aspect ratio close to one, h) the dynamical behaviors of cells, their correlation with extracellular matrix stiffness and interaction with other cells.The frontier studies on the above unexplored issues are not only important for the dusty plasma physics, but also should be able to shed some light on understanding the generic nonlinear behaviors in other corresponding nonlinear extended complex systems. The investigation will be conducted mainly experimentally and partially numerically.