In November 2016, Nature Physics, the authoritative international academic journal, reported the research work conducted by Professor Zhang Hai-Tao's group as a research highlight in the field of phase transitions of collective behavior in nature, which is entitled "Pattern phase transitions of self-propelled particles: gases, crystals, liquids, and mills". Zhang Hai-Tao was the only corresponding author for this paper. The other authors were Cheng Zhao (first author), Chen Zhiyong, T. Vicsek and Chen Duxin.

The highlight of this study, entitled "Aggregation Phenomena: Collective Diversity" reports that collective dynamics systems, such as bacteria colonies, insect swarms, fish schools, bird flocks, and mammal herds are widespread in nature. Since the pattern of biological clusters is dynamically gathering and separating, the complex evolution process has never stopped. Therefore, it is difficult to determine which stable configuration the cluster will eventually form. This work reveals that the biome clustering structure has a very similar phase transition phenomenon like the solid-liquid-gas triplet switch of water. As individual field of view increases, the cluster exhibits a phase transition from "gaseous" to "crystalline", and to "liquid"; the more interesting finding is that as the field of view expands further, a new "vortex" state yields. With the strengthening of the individual's obstacle avoidance, the "vortex" is split into three sub-states: "solid vortex ", "hollow vortex " and "single ring". This work helps to find the "key" that regulates the phase transition of a large number of clusters in nature and opens the door to the initiative regulation of unmanned system cluster, which is also of great significance to the research on panic crowd escaping.