Department of Physics, Nagoya University, Nagoya, Japan.
J Chem Phys. 2019 Feb 21;150(7):074503. doi: 10.1063/1.5086379.
We numerically investigate the slow dynamics of a binary mixture of ultrasoft particles interacting with the generalized Hertzian potential. If the softness parameter, α, is small, the particles at high densities start penetrating each other, form clusters, and eventually undergo the glass transition. We find multiple cluster-glass phases characterized by a different number of particles per cluster, whose boundary lines are sharply separated by the cluster size. Anomalous logarithmic slow relaxation of the density correlation functions is observed in the vicinity of these glass-glass phase boundaries, which hints the existence of the higher-order dynamical singularities predicted by the mode-coupling theory. Deeply in the cluster glass phases, it is found that the dynamics of a single particle is decoupled from that of the collective fluctuations.
我们通过数值方法研究了相互作用的软硬球混合物在广义赫兹势下的慢动力学。如果软度参数α较小，高密度下的粒子会开始穿透彼此，形成团簇，最终发生玻璃化转变。我们发现了多种团簇玻璃相，其特征是每个团簇中的粒子数不同，这些相的分界线由团簇大小急剧分隔开。在这些玻璃-玻璃相变边界附近，观察到密度相关函数的异常对数慢弛豫，这暗示了模式耦合理论所预测的更高阶动力学奇点的存在。在团簇玻璃相中，我们发现单个粒子的动力学与集体涨落的动力学解耦。
