标题： 具有互惠和非互惠相互作用的离散群体模型中的涌现复杂相态 显示英文标题

标题： Emergent complex phases in a discrete flocking model with reciprocal and non-reciprocal interactions

摘要： 对具有互易和非互易相互作用的多物种活性物质系统的研究兴趣正在增加。 虽然这种相互作用已经在连续对称性模型中被研究过，但对多物种离散对称性系统的了解较少。 为了解决这个问题，我们研究了双物种活性伊辛模型（TSAIM），这是双物种维克塞克模型的离散对应物。 我们的研究探讨了种间互易和非互易相互作用，以及物种转换的可能性。 在互易的TSAIM中，我们观察到了高密度平行 flocking 状态的出现，这是之前 flocking 模型中未见过的特征。 通过物种转换，TSAIM 对应于阿什金-特勒模型的活性扩展，并表现出丰富的状态图。 在非互易的 TSAIM 中，出现了跑与追的动力学。 我们还发现，由于液滴激发，系统是亚稳态的，并表现出自发的运动诱导界面钉扎。 流体动力学理论验证了我们的数值模拟并确认了相图。 显示英文摘要

摘要： There is growing interest in multi-species active matter systems with reciprocal and non-reciprocal interactions. While such interactions have been explored in continuous symmetry models, less is known about multi-species discrete-symmetry systems. To address this, we study the two-species active Ising model (TSAIM), a discrete counterpart of the two-species Vicsek model. Our investigation explores both inter-species reciprocal and non-reciprocal interactions, along with the possibility of species interconversion. In the reciprocal TSAIM, we observe the emergence of a high-density parallel flocking state, a feature not seen in previous flocking models. With species interconversion, the TSAIM corresponds to an active extension of the Ashkin-Teller model and exhibits rich state diagrams. In the non-reciprocal TSAIM, a run-and-chase dynamics emerge. We also find that the system is metastable due to droplet excitation and exhibits spontaneous motility-induced interface pinning. A hydrodynamic theory validates our numerical simulations and confirms the phase diagrams.