KINETICS OF SIMPLE REACTIONS IN A DICHOTOMIC BARRIER MODEL

We study the annihilation reaction A + A --> 0 in a 1D dichotomic barr ier model by using a Monte Carlo simulation. As a novel result, differ ent transient regimes are found for the density of A particles rho(t). Such transient regimes are strongly dependent on the parity of cell s ize L (odd or even values) and on the probability p to overcome the hi ghest barriers. The crossover times between different transient regime s obey a power-law dependence on L. A scaling relation is obtained for the intermediate and large time regimes. We also find that the asympt otic regime is strongly dependent on the initial density.