Non-Equilibrium Relaxation of Fluctuation

Abstract

It is shown that the non-equilibrium relaxation (NER) process of the order-parameter and energy is useful to study the phase transition. By observing the log-derivatives of those decay functions, the critical point is located finely and the critical exponents are estimated accurately. The major advantage of NER method is it's simplicity; not only the behavior in the large-size limit can be observed easily, but also it is not necessary to pursue the equilibrium of the system to get information of the final equilibrium state. Applications are expanding from basic systems like Ising ferromagnets, to spin-glass, quantal system, chiral and KT transitions, and so on. Now the NER process of fluctuations is also expected to share those advantages. It is found that the combinations of the NER functions of some fluctuations provide the way to determine static and dynamics critical exponents directly.