Special Session 164: Periodic and Ergodic Schrodinger Operators

Ergodicity in discrete-time quantum walks
Kiran Kumar
New York University Abu Dhabi
United Arab Emirates
Co-Author(s):    Mostafa Sabri
Abstract:
In this talk, we present some results on ergodicity for homogeneous discrete-time quantum walks on the integer lattice. The most significant result holds in dimension one and gives a complete equivalence between the absolutely continuous spectrum of the unitary operator encoding the walk and the equidistribution of its dynamics in position space. In higher dimensions, we give a criterion for full and partial ergodicity in terms of a finer property of the spectrum which we dub `No Repeating Graphs`, and distinguish how strongly the equidistribution is taking place (weak convergence vs total variation). We also present applications of our results to the ergodicity of eigenvectors for Schr\{o}dinger operators on $\mathbb{Z}$-periodic graphs.