Vojta Thomas
Department of Physics, Missouri University of Science and Technology, Rolla, Missouri 65409, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2012 Nov;86(5 Pt 1):051137. doi: 10.1103/PhysRevE.86.051137. Epub 2012 Nov 30.
The absorbing-state transition in the three-dimensional contact process with and without quenched randomness is investigated by means of Monte Carlo simulations. In the clean case, a reweighting technique is combined with a careful extrapolation of the data to infinite time to determine with high accuracy the critical behavior in the three-dimensional directed percolation universality class. In the presence of quenched spatial disorder, our data demonstrate that the absorbing-state transition is governed by an unconventional infinite-randomness critical point featuring activated dynamical scaling. The critical behavior of this transition does not depend on the disorder strength, i.e., it is universal. Close to the disordered critical point, the dynamics is characterized by the nonuniversal power laws typical of a Griffiths phase. We compare our findings to the results of other numerical methods, and we relate them to a general classification of phase transitions in disordered systems based on the rare region dimensionality.
通过蒙特卡罗模拟研究了有和没有淬火随机性的三维接触过程中的吸收态转变。在无无序的情况下，一种重加权技术与对数据到无限时间的仔细外推相结合，以高精度确定三维定向渗流普适类中的临界行为。在存在淬火空间无序的情况下，我们的数据表明吸收态转变由具有激活动力学标度的非常规无限随机性临界点控制。这种转变的临界行为不依赖于无序强度，即它是普适的。接近无序临界点时，动力学由格里菲斯相典型的非普适幂律表征。我们将我们的发现与其他数值方法的结果进行比较，并将它们与基于稀有区域维度的无序系统相变的一般分类联系起来。
