Almodóvar Alejandro, Galla Tobias, López Cristóbal
IFISC, Instituto de Física Interdisciplinar y Sistemas Complejos (CSIC-UIB), Campus Universitat de les Illes Balears, E-07122 Palma de Mallorca, Spain.
Phys Rev E. 2022 Nov;106(5-1):054130. doi: 10.1103/PhysRevE.106.054130.
We study the effects of stochastic birth and death processes on the structural phases of systems of active and passive Brownian particles subject to volume exclusion. The total number of particles in the system is a fluctuating quantity, determined by the birth and death parameters and on the activity of the particles. As the birth and death parameters are varied, we find liquid, hexatic, and solid phases. For passive particles, these phases are found to be spatially homogeneous. For active particles, motility-induced phase separation (coexisting hexatic and liquid phases) occurs for large activity and sufficiently small birth rates. We also observe a reentrant transition to the hexatic phase when the birth rate is increased. This results from a balance of an increasing number of particles filling the system, and a larger number of defects resulting from the birth and death dynamics.
我们研究了随机生灭过程对受体积排除影响的主动和被动布朗粒子系统结构相的影响。系统中粒子的总数是一个波动量，由生灭参数和粒子的活性决定。随着生灭参数的变化，我们发现了液相、六方相和固相。对于被动粒子，这些相在空间上是均匀的。对于主动粒子，当活性较大且出生率足够小时，会发生运动诱导相分离（共存的六方相和液相）。当出生率增加时，我们还观察到向六方相的再入转变。这是由于填充系统的粒子数量增加与生死动力学导致的更多缺陷之间的平衡所致。
