We have investigated numerically the quantum evolution of a delta-like wave-packet in a quenched disordered medium described by a tight-binding Hamiltonian with long-range hopping (band random matrix approach). We have obtained clean data for the scaling properties in time ana in the bandwidth b of the packet width (M) over bar and its fluctuations Delta((M) over bar) with respect to disorder realizations. We confirm that the fluctuations of the packet width in the steady-state show an anomalous scaling Delta((M) over bar)/(M) over bar similar to b(-delta) with delta = 0.75 +/- 0.03. This can be related to the presence of non-Gaussian tails in the distribution of (M) over bar. Finally, we have analysed the steady state probability profile and we have found 1/b corrections with respect to the theoretical formula derived by Zhirov in the b --> infinity limit, except at the origin, where the corrections are O(1/root b).
|Number of pages||7|
|Journal||The European Physical Journal B - Condensed Matter and Complex Systems|
|Publication status||Published - Apr 2000|
- BAND RANDOM MATRICES
- SCALING PROPERTIES
- QUANTUM CHAOS