  As discovered by P. W. Anderson, excitations do not propagate freely in a
disordered lattice, but, due to destructive interference, they localise. As a
consequence when an atom interacts with a disordered lattice one indeed
observes, a non-trivial excitation exchange between atom and lattice. Such
non-trivial atomic dynamics will in general be characterised also by a
non-trivial quantum information backflow, a clear signature of non-Markovian
dynamics. To investigate the above scenario we consider a quantum emitter, or
atom, weakly coupled to a uniform coupled-cavity array (CCA). If initially
excited, in the absence of disorder, the emitter undergoes a Markovian
spontaneous emission by releasing all its excitation into the CCA (initially in
its vacuum state). By introducing static disorder in the CCA the field normal
modes become Anderson-localized, giving rise to a non-Markovian atomic
dynamics. We show the existence of a functional relationship between a rigorous
measure of quantum non-Markovianity and the CCA localization. We furthermore
show that the average non-Markovianity of the atomic dynamics is well-described
by a phenomenological model in which the atom is coupled, at the same time, to
a single mode and to a standard - Markovian - dissipative bath.
