Overshooting and undershooting subordination scenario for fractional two-power-law relaxation responses

Phys Rev E Stat Nonlin Soft Matter Phys. 2010 Apr;81(4 Pt 1):041123. doi: 10.1103/PhysRevE.81.041123. Epub 2010 Apr 20.

Abstract

In this paper, we propose a transparent subordination approach to anomalous diffusion processes underlying the nonexponential relaxation. We investigate properties of a coupled continuous-time random walk that follows from modeling the occurrence of jumps with compound counting processes. As a result, two different diffusion processes corresponding to over- and undershooting operational times, respectively, have been found. We show that within the proposed framework, all empirical two-power-law relaxation patterns may be derived. This work is motivated by the so-called "less typical" relaxation behavior observed, e.g., for gallium-doped Cd0.99Mn0.01Te mixed crystals.

Publication types

  • Research Support, Non-U.S. Gov't