Abstract
We study the coherent electron backscattering interference in the presence of electron dephasing in 2D/3D non-uniform (NU) disordered systems, within our virtual electron trap scattering (VETS) model, where the dephasing rate 1/τ <sub>φ</sub> is taken to be due to the inelastic electronelectron or electronphonon scattering. A possible saturation mechanism of apparent electronic dephasing is examined. The system considered is composed of two kinds of subsystems, namely, L-islands and H-region with contrasting diffusion constants, of which the L-islands (of low diffusion constant) act as virtual electron traps randomly dispersed in the percolating H-background (of high diffusion constant). The physics of VETS model is characterized by the two important dwell times, τ <sub>f</sub> and τ <sub>b</sub> , with τ <sub>f</sub> /τ <sub>b</sub> being the mean duration for which an electron wanders in the H-region/L-island before it leaves the region, respectively. In order to make connection with experiments, we introduce the notion of an effective system of uniform (U) disorder with a dephasing time <sup>τφ</sup> ( <sup>effective)</sup> , which simulates in the aspect of backscattering the NU system being studied. The effective dephasing time <sup>τφ</sup> ( <sup>effective)</sup> thus introduced is a function of τ <sub>φ</sub> , and the function, <sup>τφ</sup> ( <sup>effective)</sup> (τ <sub>φ</sub> ), is derived and examined. If τ <sub>b</sub> τ <sub>f</sub> , an interesting phenomenon occurs in the range of temperature (T) where the true dephasing time τ <sub>φ</sub> (T) lies between τ <sub>f</sub> and τ <sub>b</sub> , i.e., τ <sub>f</sub> <τ <sub>φ</sub> (T)<τ <sub>b</sub> . In this case, we obtain <sup>τφ</sup> ( <sup>effective)</sup> (τ <sub>φ</sub> ) ≈τ <sub>f</sub> , which is insensitive to the variation in τ <sub>φ</sub> (or T) and shows the signature of <sup>τφ</sup> ( <sup>effective)</sup> saturation. However, at the further lowered temperature where τ <sub>φ</sub> (T)≥τ <sub>b</sub> , <sup>τφ</sup> ( <sup>effective)</sup> rises up sharply without being saturated. © 2011 Elsevier B.V.