Dynamical localization for random scattering zippers

TL;DR

This paper proves dynamical localization for a random scattering zipper model by analyzing Lyapunov exponents and resolvent decay, demonstrating exponential decay of transfer matrix products and resolvent coefficients.

Contribution

It introduces a novel approach to establish dynamical localization for a specific class of random unitary operators using fractional moments and transfer matrix analysis.

Findings

Lyapunov exponents are continuous and strictly positive around the unit circle.

Exponential decay of transfer matrix products is established.

Finite resolvent coefficients decay exponentially, implying dynamical localization.

Abstract

This article establishes a proof of dynamical localization for a random scattering zipper model. The scattering zipper operator is the product of two unitary by blocks operators, multiplicatively perturbed on the left and right by random unitary phases. One of the operator is shifted so that this configuration produces a random 5-diagonal unitary operator per blocks. To prove the dynamical localization for this operator, we use the method of fractional moments. We first prove the continuity and strict positivity of the Lyapunov exponents in an annulus around the unit circle, which leads to the exponential decay of a power of the norm of the products of transfer matrices. We then establish an explicit formula of the coefficients of the finite resolvent in terms of the coefficients of the transfer matrices using Schur's complement. From this we deduce, through two reduction results, the exponential decay of the resolvent, from which we get the dynamical localization.