Zhu Han, Zhu Jian-Yang, Zhou Yang
Department of Physics, Nanjing University, China.
Phys Rev E Stat Nonlin Soft Matter Phys. 2002 Sep;66(3 Pt 2A):036106. doi: 10.1103/PhysRevE.66.036106. Epub 2002 Sep 10.
In this paper, we have given a systematic formulation of a generalized competing mechanism: The Glauber-type single-spin transition mechanism, with probability p, simulates the contact of the system with the heat bath, and the Kawasaki-type spin-pair redistribution mechanism, with probability 1-p, simulates an external energy flux. These two mechanisms are natural generalizations of Glauber's single-spin flipping mechanism and Kawasaki's spin-pair exchange mechanism respectively. On the one hand, the proposed mechanism is, in principle, applicable to arbitrary systems, while on the other hand, our formulation is able to contain a mechanism that just directly combines single-spin flipping and spin-pair exchange in their original form. Compared with the conventional mechanism, the proposed mechanism does not assume the simplified version and leads to a greater influence of temperature. The fact, order for lower temperature and disorder for higher temperature, will be universally true. In order to exemplify this difference, we applied the mechanism to the one-dimensional Ising model and obtained analytical results. We also applied this mechanism to the kinetic Gaussian model and found that above the critical point there will be only paramagnetic phase, while below the critical point, the self-organization as a result of the energy flux will lead the system to an interesting heterophase, instead of the initially guessed antiferromagnetic phase. We studied this process in details.
在本文中,我们给出了一种广义竞争机制的系统表述:以概率(p)的格劳伯型单自旋跃迁机制模拟系统与热浴的接触,以概率(1 - p)的川崎型自旋对重新分布机制模拟外部能量通量。这两种机制分别是格劳伯单自旋翻转机制和川崎自旋对交换机制的自然推广。一方面,所提出的机制原则上适用于任意系统,另一方面,我们的表述能够包含一种直接将单自旋翻转和自旋对交换以其原始形式结合的机制。与传统机制相比,所提出的机制不采用简化版本,并且导致温度的影响更大。低温时有序、高温时无序这一事实将普遍成立。为了例证这种差异,我们将该机制应用于一维伊辛模型并得到了分析结果。我们还将此机制应用于动力学高斯模型,发现高于临界点时只有顺磁相,而低于临界点时,能量通量导致的自组织将使系统进入一个有趣的异相,而不是最初猜测的反铁磁相。我们详细研究了这个过程。