Transient relaxation of tightly confined 3D Yukawa liquids after quenching

For the cold liquid confined in a mesoscopic gap, the flat boundaries constrain transverse particle motion and cause the formation of layers parallel to boundaries, favoring intralayer triangular packing. This results in different behaviors compared to the bulk liquid. In this work, we numerically investigate the transient relaxation dynamics, associated with the inward propagations of layering and intra-/interlayer orders, after quenching the tightly confined Yukawa liquid by two parallel flat boundaries. We find that quenching the hot liquid to the transition temperature TL of fully layering leads to an initial rapid rise of the layering order, followed by the successive formation of small intralayer crystalline ordered domains (ICODs) with various intralayer lattice orientations (ILOs), from the outmost layers. These ICODs gradually coalesce into two-dimensional monocrystals in the two opposite outmost layers. Through interlayer coupling, this process propagates inward, led by fluctuating fronts. Behind those fronts, three-dimensional (3D) CODs in which layers share the same ILO are formed. In the inner region, where the two fronts meet, the competition of the different ILOs anchored by those of the two opposite outmost layers causes strong spatiotemporal fluctuations of ILOs. This continues until nearly the entire region within the gap, except for one of the two outmost layers, becomes a large 3D monocrystal with the same ILOs. Quenching to a lower temperature (0.4 TL) accelerates the above processes. However, the much weaker thermal agitation turns the system into a glassy state after forming large 3D CODs with different ILOs, which evolve slowly.