  We investigate the dynamical properties of the XY spin 1/2 chain with
infinite-range transverse interactions and find a dynamical phase transition
with a chaotic dynamical phase. In the latter, we find non-vanishing
finite-time Lyapunov exponents and intermittent behavior signaled by fast and
slow entropy growth periods. Further, we study the XY chain with a local
self-consistent transverse field and observe a localization phase transition.
We show that localization stabilizes the chaotic dynamical phase.
