Yeo Kyongmin, Lushi Enkeleida, Vlahovska Petia M
IBM T.J. Watson Research Center, Yorktown Heights, New York 10598, USA.
Division of Applied Mathematics, Brown University, Rhode Island 02912, USA.
Phys Rev Lett. 2015 May 8;114(18):188301. doi: 10.1103/PhysRevLett.114.188301. Epub 2015 May 5.
We study, numerically, the collective dynamics of self-rotating nonaligning particles by considering a monolayer of spheres driven by constant clockwise or counterclockwise torques. We show that hydrodynamic interactions alter the emergence of large-scale dynamical patterns compared to those observed in dry systems. In dilute suspensions, the flow stirred by the rotors induces clustering of opposite-spin rotors, while at higher densities same-spin rotors phase separate. Above a critical rotor density, dynamic hexagonal crystals form. Our findings underscore the importance of inclusion of the many-body, long-range hydrodynamic interactions in predicting the phase behavior of active particles.
我们通过考虑由恒定顺时针或逆时针扭矩驱动的单层球体，对自旋转非对齐粒子的集体动力学进行了数值研究。我们表明，与在干燥系统中观察到的情况相比，流体动力相互作用改变了大规模动力学模式的出现。在稀悬浮液中，转子搅拌产生的流动会导致反自旋转子聚集，而在较高密度下，同自旋转子会发生相分离。超过临界转子密度时，会形成动态六角晶体。我们的研究结果强调了在预测活性粒子的相行为时考虑多体、长程流体动力相互作用的重要性。
