玻璃形成液體的微觀結構與微觀動力學是個有趣且重要的議題。在過去的玻璃形成液體研究之中，動力異質性（即為共存的侷限顫動和侷限跳躍運動）以及其結構相關之起源受到廣大的關注。在液體淬火之後，結構整齊度會隨著增長等待時間而增長，導致被缺陷團簇所分隔開來的局域整齊區塊也隨之形成。除此之外，粒子運動之間的關聯性也由於熱擾動在低溫狀態下被抑制而提昇。因此，在玻璃形成液體中，粒子可以影響它周圍的粒子進而形成帶狀運動，而不僅僅只有線狀的崩盤合作侷限跳躍運動。然而，局域整齊區塊的演化以及合作的粒子運動之間的關係至今仍是難以捉摸的。 在這工作中，我們淬火一個由懸浮於低氣壓氬氣射頻游離之帶電微粒所形成的二維微粒電漿液體，並直接使用光學顯微鏡去研究局部整齊區域在時空中的演化。局域整齊區塊可藉由鍵方向次序來認定。利用我們新開發的量測，集體性的粒子激發運動則可以被分類為旋轉激發運動、伸長運動、壓縮運動、以及剪切運動。這個新量測方法是考慮由兩個相鄰最近的粒子所形成之等效鍵的靜態與動態行為。除此之外，它可以認定局域應變在局域整齊區塊演化過程中的空間分佈。最後，我們利用粒子激發運動之間的轉換來探討一個二維淬火液體之中的二維結構重整的機制。 The micro-structure and micro-dynamics of glass-forming liquids are interesting and important issues. The dynamical heterogeneity, which is the coexistence of cage rattling and cage jumping of particle, and its structural origin have attracted much attention in the glass-forming liquid. It is also found that the structural order increases with the increase of waiting time after quenching, resulting in the formation of local ordered domains separated by defect clusters. Furthermore, the particle motions become strongly correlated due to the suppression of thermal agitation at low temperature. Instead of string-like avalanche cooperative cage jumping in liquid, particles can affect their neighbors and form band-like motion in the glass-forming liquid. However, the relation between the evolution of local ordered domains and the cooperative particle motions is still elusive. In this work, the spatiotemporal evolution of local ordered domains and structural rearrangement in a quenched 2D dusty plasma liquid formed by the charged dust particles suspended in a low pressure argon rf discharge are experimentally investigated through direct optical microscopy. The local ordered domains are identified by the bond orientational order of particle. The collective excitations of particles are classified into vortical excitation, elongation, compression, and shear motion by our new measurement associated with the effective bond connecting pair of the nearest neighbor particles. It is found that the local ordered domains can be ruptured by the small spatial scale collective excitations of particles. Our new measurement not only characterizes the collective excitations of particles, but also identified the spatial distribution of local strain during the domain evolution. Finally, the mechanism of 2D structural rearrangement in a 2D quenched liquid is explained through the change of the collective excitations of particles.
