  A longstanding puzzle for the lowest Landau level crystal phase has been an
order of magnitude discrepancy between the theoretically calculated energy of
the defects and the measured activation gap. We perform an extensive study of
various kinds of defects in the correlated composite fermion crystal and find
that the lowest energy defect is a six-fold symmetric "hyper-correlated bubble
interstitial," in which an interstitial particle forms a strongly correlated
bound state with a particle of the crystal. The energy of the bubble defect is
a factor of $\sim$3 smaller than that of the lowest energy defect in a
Hartree-Fock crystal. The anomalously low activation energies measured in
transport experiments are thus a signature of the unusual quantum nature of the
crystal and its defects.
