Avalanche activities through spatiotemporally cascaded excitations of heterogeneous multiscale acoustic waves in cold dusty plasma liquids

Hao-Wei Hu^1*, Yi-Cheng Zhao¹, Lin I¹

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

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

In various strongly coupled complex systems, avalanche activities like seismic activities and epidemic spreading can uncertainly occur, spread, and terminate, in the form of multiscale clusters in the spatiotemporal space. Understanding the generic behavior of clusters, and the formation of extreme activities with large cluster sizes, are important issues. Here, using a cold dusty plasma liquid, formed by micrometer-sized dust particles negatively charged and suspended in the low-pressure plasma, as a platform, we experimentally addressed the above issues [1]. Close to the freezing point, cold liquids composed of crystalline ordered domains surrounded by defect clusters can support the thermally excited microscopic acoustic wave turbulence, and exhibit structural rearrangements (SR) in the form of multiscale clusters as avalanche activities. It is found that the region with many widely spread defects can form a large preceding skeleton of pool structural order through thermal excitations of slow wave modes, which facilitates the latter cascaded sequential excitations from slow to fast wave modes. The spatiotemporally cascaded intermittent phase synchronization (desynchronization) of large amplitude different-scale wave modes can lead to the onset and spreading (termination) of SR clusters. The gradual excitation and amplitude of coarse-grained slow modes, and the number and radius gyration of defects around the preceded skeleton with pool structural order, can be used as precursors for the warning extreme avalanche SR.

[1] H. W. Hu, Y. C. Zhao, and L. I, Phys. Rev. Research 4, 023116 (2022)

Keywords: Dusty plasma, Avalanche activity, Microscopic acoustic wave turbulence