Generalized autocorrelation function in the family of deterministic and stochastic anomalous diffusion processes

Abstract

We investigate the observables of the one-dimensional model for anomalous transport in semiconductor devices where diffusion arises from scattering at dislocations at fixed random positions, known as L\'evy-Lorentz gas. Due to complex stochasticity in the system, direct investigations of such non-trivial dynamics are not possible; therefore, to gain insight into the microscopic properties, we use deterministic dynamics known as the Slicer Map and Fly-and-Die dynamics. We analytically derive the generalized position auto-correlation function of these dynamics and study the special case, the 3-point position correlation function. For this, we derive single parameter-dependent scaling and compare it with the numerically estimated 3-point position auto-correlation of the L\'evy-Lorentz gas, for which the analytical expression is still an open question. Here we obtained a remarkable agreement between them, irrespective of any functional relationship with time. Moreover, we demonstrate that the position moments and the position auto-correlations of these systems scale in the same fashion, provided the times are large enough and far enough apart. Other observables, such as velocity moments and correlations, are reported to distinguish the systems.