具有无规分布陷阱点阵上的连续时间无规行走

用连续时间无规行走(CTRW)理论处理陷阱控制的无序点阵上的无规行走问题,首次导出行走者可有自发衰变及受陷态具有有限寿命情形下,行走者存活几率P(t)满足的方程。对一种广泛使用的等待时间分布密度ψ(t)=ααt^-(1-α)exp(-αt^α)0<α≤1,在受陷态寿命无限长情况下,给出适用于任意陷阱浓度和任意时间的P(t)的级数解。结合实验事实和Ngai的低能激发理论,指出同时考虑动力学关联和结构无序对解释实际过程的必要性。并提出包括可由Ngai低能激发理论描写的动力学关联在内的连续时间无规行走理论,其物理图象与目前的CTRW理论有根本不同。 关键词：

CONTINUOUS TIME RANDOM WALKS ON RANDOM LATTICES WITH TRAPS

Random walks on random lattices with traps is treated by continuous time random walk (CTRW) method. The equation of walker's survival probability P(t) is obtained in the general case that the walker can decay spontaneously and is able to escape from the well after trapping. In the case of deep traps, the series solution for all time and arbitrary trap concentration with the waiting time distrubution density ψ(t) = ααt^-(1-α) exp(-at^a), 0 <α≤ 1, is given. Recognizing the experimental facts and Ngai's low energy excitations theory, we point out the importance of dynamic coupling. To describe this dynamic coupling, a theory of CTRW on real random lattices is proposed. In this approach the physical picture is completely different from the curresnt CTRW theory.