  We revisit here the dynamics of an engineered dimer granular crystal under an
external periodic drive in the presence of dissipation. Earlier findings
included a saddle-node bifurcation, whose terminal point initiated the
observation of chaos; the system was found to exhibit bistability and potential
quasiperiodicity. We now complement these findings by the identification of
unstable manifolds of saddle periodic solutions (saddle points of the
stroboscopic map) within the system dynamics. We unravel how homoclinic tangles
of these manifolds lead to the appearance of a chaotic attractor, upon the
apparent period-doubling bifurcations that destroy invariant tori associated
with quasiperiodicity. These findings complement the earlier ones, offering
more concrete insights into the emergence of chaos within this
high-dimensional, experimentally accessible system.
