Transfer tensor analysis of localization in the Anderson and Aubry-Andr\'e-Harper models

Abstract

We use the transfer tensor method to analyze localization and transport in simple disordered systems, specifically the Anderson and Aubry-Andr\'e-Harper models. Emphasis is placed on the memory effects that emerge when ensemble-averaging over disorder, even when individual trajectories are strictly Markovian. We find that transfer tensor memory effects arise to remove fictitious terms that would correspond to redrawing static disorder at each time step, which would create a temporally uncorrelated dynamic disorder. Our results show that while eternal memory is a necessary condition for localization, it is not sufficient. We determine that signatures of localization and transport can be found within the transfer tensors themselves by defining a metric called "outgoing-pseudoflux". This work establishes connections between theoretical research on dynamical maps and Markovianity and localization phenomena in physically realizable model systems.