Density-matrix renormalization-group study of current and activity fluctuations near nonequilibrium phase transitions.
Density-matrix renormalization-group study of current and activity fluctuations near nonequilibrium phase transitions.
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非平衡相变附近电流和活动波动的密度矩阵重整化群研究。
DOI：
10.1103/physreve.79.020101
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
C. Vanderzande
中科院分区：
文献类型：
--
作者：
Mieke Gorissen;J. Hooyberghs;C. Vanderzande
波动电流的累积量可以从类自由能生成函数中得到，对于马尔可夫过程，它等于广义生成元的最大特征值。我们用随机系统的密度矩阵重整化群来确定这个本征值。我们计算了完全不对称排斥过程在不同阶段和相变时电流的方差。我们的结果可以描述在一个涉及到动力学指数z的标度系数的条款。我们还计算了接触过程的吸收态跃迁附近的动力学活动（构型变化总数）的母函数。它的标度特性可以用已知的临界指数来表示。
Cumulants of a fluctuating current can be obtained from a free-energy-like generating function, which for Markov processes equals the largest eigenvalue of a generalized generator. We determine this eigenvalue with the density-matrix renormalization group for stochastic systems. We calculate the variance of the current in the different phases, and at the phase transitions, of the totally asymmetric exclusion process. Our results can be described in the terms of a scaling ansatz that involves the dynamical exponent z . We also calculate the generating function of the dynamical activity (total number of configuration changes) near the absorbing-state transition of the contact process. Its scaling properties can be expressed in terms of known critical exponents.