Hayashi Kumiko, Sasa Shin-ichi
Department of Pure and Applied Sciences, University of Tokyo, Komaba, Tokyo 153-8902, Japan.
Phys Rev E Stat Nonlin Soft Matter Phys. 2003 Sep;68(3 Pt 2):035104. doi: 10.1103/PhysRevE.68.035104. Epub 2003 Sep 22.
We explore thermodynamic relations in nonequilibrium steady states with numerical experiments on a driven lattice gas. After operationally defining the pressure and chemical potential in the driven lattice gas, we confirm numerically the validity of the integrability condition (the Maxwell relation) for the two quantities whose values differ from those for an equilibrium system. This implies that a free-energy function can be constructed for the nonequilibrium steady state that we consider. We also investigate a fluctuation relation associated with this free-energy function. Our result suggests that the compressibility can be expressed in terms of density fluctuations even in nonequilibrium steady states.
我们通过对驱动晶格气体进行数值实验，探索非平衡稳态下的热力学关系。在对驱动晶格气体中的压力和化学势进行操作定义后，我们通过数值方法证实了可积性条件（麦克斯韦关系）对于两个量的有效性，这两个量的值与平衡系统中的值不同。这意味着可以为我们所考虑的非平衡稳态构建一个自由能函数。我们还研究了与该自由能函数相关的涨落关系。我们的结果表明，即使在非平衡稳态下，压缩性也可以用密度涨落来表示。
