非对称排斥过程中的稳态性质

Steady-state Properties in the Asymmetric Exclusion Process

通过数值模拟研究了ASEP模型的稳态性质,主要考察了当注入概率α和输出概率β变化时系统稳态密度和流量表现出的相变性质.研究发现,同以往TASEP模型的结果相比较,ASEP模型中系统的稳态密度具有相似的性质,然而其稳态流量表现出非常显著的新特性.首先,在TASEP模型中一个很大参数范围内存在的极大流量区在ASEP模型中退化为一个临界值,系统的极大流量仅仅当注入概率α等于某一临界值cα时才出现.此外,研究发现ASEP模型中存在着一个TASEP模型不具备的流量随注入概率α的增加而递减的流量减小区.

We study the steady-state properties of the ASEP model by means of numerical simulations, focusing on the phase diagram of density and current of the system under the steady-state when the injection probability α and the extraction probability β are varied. It is found that, the steady-state density property of ASEP model is similar to that of the previously studied TASEP model, while its steady-state current exhibits some novel properties. Firstly, the nontrivial maximal current phase in the TASEP model degenerates into a critical one, and the maximal current of the system can be obtained only when the injection probability α equals to a critical value αc. Moreover, it is found that, in the ASEP model, there exists a new phase in which current is decreased with the increase of α, which is absent from the previous results obtained in the TASEP model.