论文标题
活跃的极地羊群出生和死亡
Active polar flock with birth and death
论文作者
论文摘要
我们在二维底物上研究了自polpelled极性颗粒的集合，该颗粒具有出生和死亡。我们使用主动ising旋转引入了系统的最小晶格模型，每个粒子都可以具有两个可能的方向。该活动被建模为粒子沿其方向的偏置运动。这些颗粒还使用大都市蒙特卡洛算法与他们最近的邻居保持一致。系统通过调整系统的温度来显示疾病到阶的过渡。此外，颗粒的出生和死亡是通过出生和死亡率$γ$引入的。该系统是在障碍过渡的附近进行的。无序转变的性质显示了从一阶开始的交叉，由于我们从零到有限的值调整了$γ$，因此不连续到连续类型。我们还使用重量化的平均场理论编写了局部阶参数的有效自由能，并确认了相变的性质对出生和死亡率参数的依赖性。
We study a collection of self-propelled polar particles on a two-dimensional substrate with birth and death. We introduce a minimal lattice model for the system using active Ising spins, where each particle can have two possible orientations. The activity is modeled as a biased movement of the particle along its direction of orientation. The particles also align with their nearest neighbors using Metropolis Monte-Carlo algorithm. System shows a disorder-to-order transition by tuning the temperature of the system. Additionally, the birth and death of the particles is introduced through a birth and death rate $γ$. The system is studied near the disorder-to-order transition. The nature of disorder-to-order transition shows a crossover from first order, discontinuous to continuous type as we tune $γ$ from zero to finite values. We also write the effective free energy of the local order parameter using renormalised mean field theory and it confirms the dependence of the nature of phase transition on the birth and death rate parameter.
