46 research outputs found
The problem of quantum chaotic scattering with direct processes reduced to the one without
We show that the study of the statistical properties of the scattering matrix
S for quantum chaotic scattering in the presence of direct processes
(charaterized by a nonzero average S matrix ) can be reduced to the simpler
case where direct processes are absent ( = 0). Our result is verified with a
numerical simulation of the two-energy autocorrelation for two-dimensional S
matrices. It is also used to extend Wigner's time delay distribution for
one-dimensional S matrices, recently found for = 0, to the case not
equal to zero; this extension is verified numerically. As a consequence of our
result, future calculations can be restricted to the simpler case of no direct
processes.Comment: 9 pages (Latex) and 1 EPS figure. Submitted to Europhysics Letters.
The conjecture proposed in the previous version is proved; thus the present
version contains a more satisfactory presentation of the proble
Wave transport in one-dimensional disordered systems with finite-width potential steps
An amazingly simple model of correlated disorder is a one-dimensional chain
of n potential steps with a fixed width lc and random heights. A theoretical
analysis of the average transmission coefficient and Landauer resistance as
functions of n and klc predicts two distinct regimes of behavior, one marked by
extreme sensitivity and the other associated with exponential behavior of the
resistance. The sensitivity arises in n and klc for klc approximately pi, where
the system is nearly transparent. Numerical simulations match the predictions
well, and they suggest a strong motivation for experimental study.Comment: A6 pages. 5 figures. Accepted in EP