248 research outputs found
Delocalization in One-Dimensional Tight-Binding Models with Fractal Disorder
In the present work, we investigated the correlation-induced
localization-delocalization transition in the one-dimensional tight-binding
model with fractal disorder. We obtained a phase transition diagram from
localized to extended states based on the normalized localization length by
controlling the correlation and the disorder strength of the potential. In
addition, the transition of the diffusive property of wavepacket dynamics is
shown around the critical point.Comment: 9 pages, 11 figure
Wavepacket Dynamics in One-Dimensional System with Long-Range Correlated Disorder
We numerically investigate dynamical property in the one-dimensional
tight-binding model with long-range correlated disorder having power spectrum
(spectrum exponent) generated by Fourier filtering
method. For relatively small time-dependence of mean
square displacement (MSD) of the initially localized wavepacket shows ballistic
spread and localizes as time elapses. It is shown that dependence of
the dynamical localization length (DLL) determined by the MSD exhibits a simple
scaling law in the localization regime for the relatively weak disorder
strength . Furthermore, scaled MSD by the DLL almost obeys an universal
function from the ballistic to the localization regime in the various
combinations of the parameters and .Comment: 4 pages, 4 figure
Time-reversal Characteristics of Quantum Normal Diffusion
This paper concerns with the time-reversal characteristics of intrinsic
normal diffusion in quantum systems. Time-reversible properties are quantified
by the time-reversal test; the system evolved in the forward direction for a
certain period is time-reversed for the same period after applying a small
perturbation at the reversal time, and the separation between the time-reversed
perturbed and unperturbed states is measured as a function of perturbation
strength, which characterizes sensitivity of the time reversed system to the
perturbation and is called the time-reversal characteristic.
Time-reversal characteristics are investigated for various quantum systems,
namely, classically chaotic quantum systems and disordered systems including
various stochastic diffusion systems. When the system is normally diffusive,
there exists a fundamental quantum unit of perturbation, and all the models
exhibit a universal scaling behavior in the time-reversal dynamics as well as
in the time-reversal characteristics, which leads us to a basic understanding
on the nature of quantum irreversibility.Comment: 21pages, 25figure
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