  A rapidly rotating and highly magnetized neutron star (NS) could be formed
from the explosive phenomena such as superluminous supernovae and gamma-ray
bursts. This newborn NS can substantially influence the emission of these
explosive transients through its spin-down. The spin-down evolution of the NS
can sometimes be affected by fallback accretion, although it is usually
regulated by the magnetic dipole radiation and gravitational wave radiation of
the NS. Under appropriate conditions, the accreting material can be firstly
ejected and subsequently recycled back, so that the accretion disk can keep in
a quasi-steady state for a long time. Here we describe the interaction of the
NS with such a propeller-recycling disk and their co-evolution. Our result
shows that, the spin-down of the NS can be initially dominated by the
propeller, which prevents the disk material from falling onto the NS until
hundreds or thousands of seconds later. It is suggested that the abrupt fall of
the disk material onto the NS could significantly suppress the magnetic dipole
radiation and then convert the NS from a normal magnetar to a low-field
magnetar. This evolution behavior of the newborn NS can help to understand the
very different influence of the NS on the early GRB afterglows and the late
supernova/kilonova emission.
