Touma Jihad R, Shreim Amer, Klushin Leonid I
Department of Physics, American University of Beirut, Beirut, Lebanon.
Phys Rev E Stat Nonlin Soft Matter Phys. 2010 Jun;81(6 Pt 2):066106. doi: 10.1103/PhysRevE.81.066106. Epub 2010 Jun 8.
We undertake a systematic numerical exploration of self-organized states in a deterministic model of interacting self-propelled particles in two dimensions. In the process, we identify various types of collective motion, namely, disordered swarms, rings, and droplets. We construct a "phase diagram," which summarizes our results as it delineates phase transitions (all discontinuous) between disordered swarms and vortical flocks on one hand and bound vortical flocks and expanding formations on the other. One of the transition lines is found to have a close analogy with the temperature-driven gas-liquid transition, in finite clusters with the same interparticle potential. Furthermore, we report on a type of flocking which takes place in the presence of a uniform external driver. Altogether, our results set a rather firm stage for experimental refinement and/or falsification of this class of models.
我们对二维相互作用的自驱动粒子确定性模型中的自组织状态进行了系统的数值探索。在此过程中，我们识别出了各种类型的集体运动，即无序群、环和液滴。我们构建了一个“相图”，它总结了我们的结果，因为它描绘了一方面无序群和涡旋群之间、另一方面束缚涡旋群和扩展形态之间的相变（均为不连续相变）。发现其中一条转变线与具有相同粒子间势的有限团簇中温度驱动的气-液转变有密切的相似性。此外，我们报告了一种在均匀外部驱动力存在下发生的聚集类型。总之，我们的结果为这类模型的实验改进和/或证伪奠定了相当坚实的基础。
