SCALING OF SPATIOTEMPORAL CORRELATION IN ORDERING DYNAMICS

The two-time scaling assumption in the system undergoing phase separation is studied numerically. This assumption is written for the order-parameter correlation function as Sk(t,t)[Sk(t)Sk(t)]-1/2 =V(kR(t),t/t), where k is the wave number, t and t are times after the quench, R(t) is the length scale, and Sk(t) is the same-time correlation function, which scales as Sk(t)=R(t)dS (kR(t)), with d being the spatial dimension. We also examine a power-law expansion of V(0,x)(1+/2)x-x1+/2 (x1). Here 01+/2, and =d/z-2 for the nonconserved order parameter and =(d+4)/z-2 for the conserved order parameter, where z is the growth-law exponent: R(t)z t. For the two-dimensional Ising spin system with Glauber dynamics, we have =-1, and by simulation we found 0.15. We have also done the same analysis for a two-dimensional system with conserved order parameter. © 1990 The American Physical Society.