Structural rearrangements in microscopic acoustic wave turbulence of cold dusty plasma liquids

Hao-Wei Hu^1*, Lin I¹

¹Department of Physics, National Central University, Jhongli, Taiwan

* Presenter:Hao-Wei Hu, email:yosino0311@gmail.com

Structural rearrangement (SR) is a fundamental phenomenon ubiquitously occurring in many strongly-coupled systems such as cold liquids, glass-forming liquids, and glasses. Previous studies mainly focused on the prediction of the uncertain SR event by investigating its correlation with different-scale dynamical variables or structural orders, but to a lesser extent on spatiotemporal behaviors of SR. In particular, SR has not ever been investigated from the view of the superposition of thermally excited microscopic acoustic waves. Dusty plasma liquid formed by micrometer-sized dust particles negatively charged and suspended in the low-pressure glow discharge is a good platform for direct visualization of the microstructure and motion at the microscopic level. In this work, we experimentally investigate the spatiotemporal behavior of structural rearrangements and their correlation with multiscale acoustic waves in quasi-two-dimensional cold dusty plasma liquids. Through multidimensional complementary ensemble empirical mode decomposition (MCEEMD), the dust particle trajectories are decomposed into different-scale traveling wave modes. It is found that in the ordered region with disclination defect, the spatiotemporal phase synchronization of traveling large-amplitude low-frequency wave modes in the xyt space, is the key to induce SR and the subsequent string-like cooperative hopping. The region with large-scale poor interlocking causes the easier excitation of the low-frequency wave mode, which facilitates the occurrence of SR event.

Keywords: Dusty Plasma, Cold liquid, Microscopic acoustic wave turbulence, Structural rearrangement