Surface-Induced Layering of Quenched 3D Dusty Plasma Liquids: Micromotion and Structural Rearrangement.

Abstract

We experimentally demonstrate confinement surface induced layering with a fluctuating layering front, and investigate the heterogeneous 3D crystalline ordered structure, cooperative micromotion, and structural rearrangement in the layered region of a quenched dusty plasma liquid. It is found that, after quenching the liquid with 2 to 3 layers adjacent to its flat bottom boundary, the layering front invades upward and exhibits turbulentlike fluctuations with power law decays in spatial and temporal power spectra. The layered region can be viewed as a 2+1D system with vertically coupled horizontal 2D layers, in which particle translayer motions are nearly fully suppressed. Each layer exhibits hexatic structure with a slow decay of long-range triangular lattice order. The nearly parallel but with different horizontal shifts of intralayer lattice lines of adjacent layers allows the heterogeneous fcc, bcc, and hcp structures with specific lattice orientations. In each layer, particles exhibit thermally excited horizontal motions of alternative cage rattling and cooperative hopping, which cause intralayer lattice line wiggling and triangular crystalline domain rupture or healing, respectively. The different intralayer cooperative motion of adjacent layers is the key for interlayer slip causing the structural rearrangement of 3D crystalline ordered domains.