Localization for random perturbations of periodic Schroedinger operators with regular Floquet eigenvalues

Abstract

We prove a localization theorem for continuous ergodic Schr\"odinger operators $ H_\omega := H_0 + V_\omega $, where the random potential $ V_\omega $ is a nonnegative Anderson-type perturbation of the periodic operator $ H_0$. We consider a lower spectral band edge of $ \sigma (H_0) $, say $ E= 0 $, at a gap which is preserved by the perturbation $ V_\omega $. Assuming that all Floquet eigenvalues of $ H_0$, which reach the spectral edge 0 as a minimum, have there a positive definite Hessian, we conclude that there exists an interval $ I $ containing 0 such that $ H_\omega $ has only pure point spectrum in $ I $ for almost all $ \omega $.