We revisit motility-induced phase separation in two models of active particles interacting by pairwise repulsion and uncover new qualitative features: the resulting dense phase contains gas bubbles distributed algebraically up to a typically extremely large cutoff scale. At large enough system size and/or global density, all the gas may be contained inside the bubbles, at which point the system is microphase separated with a finite cutoff bubble scale. We further observe that the ordering is clearly anomalous, with different dynamics for the coarsening of the dense phase and of the gas bubbles. This self-organized critical phenomenology is reproduced by a “reduced bubble model” that implements the basic idea of reverse Ostwald ripening put forward in Tjhung et al. [Phys. Rev. X 8, 031080 (2018)].

中文翻译：

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排斥活性粒子中的自组织临界共存相

我们在通过成对排斥相互作用的两种活性颗粒模型中重新研究了由运动引起的相分离，并揭示了新的定性特征：形成的致密相包含代数分布的气泡，其截止尺寸通常非常大。在足够大的系统尺寸和/或整体密度下，所有气体都可能包含在气泡内部，此时，系统会以有限的截止气泡比例进行微相分离。我们进一步观察到，这种排列显然是异常的，对于致密相和气泡的粗化具有不同的动力学。这种自组织的临界现象是由“减少的气泡模型”再现的，该气泡模型实现了Tjhung等人提出的逆奥斯特瓦尔德成熟的基本思想。[物理 X 8版，031080（2018）]。