  We exhibit a remarkable equivalence between the dynamics of an intermittent
nonlinear map and the electronic transport properties (obtained via the
scattering matrix) of a crystal defined on a double Cayley tree. This strict
analogy reveals in detail the nature of the mobility edge normally studied near
(not at) the metal-insulator transition in electronic systems. We provide an
analytical expression for the conductance as function of system size that at
the transition obeys a q-exponential form. This manifests as power-law decay or
few and far between large spike oscillations according to different kinds of
boundary conditions.
