Copyright © 2005 Hindawi Publishing Corporation. All rights reserved.
Localization lengths for Schrödinger operators on
2 with decaying random potentials
We study a class of Schrödinger operators on
2 with a random potential decaying as |x|–
, 0<
1/2, in the limit of small disorder strength
. For the critical exponent
=1/2, we prove that the localization length of eigenfunctions is bounded below by
, while for 0<
<1/2, the lower bound is
–(2–
)/(1–2
), for any
>0. These estimates "interpolate" between the lower bound
–2+
due to recent work of Schlag-Shubin-Wolff for
=0, and pure a.c. spectrum for
>1/2 demonstrated in recent work of Bourgain.