  Quantum entanglement, the essential resource for quantum information
processing, has rich dynamics under different environments. Probing different
entanglement dynamics typically requires exquisite control of complicated
system-environment coupling in real experimental systems. Here, by a simple
control of the effective solid-state spin bath in a diamond sample, we observe
rich entanglement dynamics, including the conventional asymptotic decay as well
as the entanglement sudden death, a term coined for the phenomenon of complete
disappearance of entanglement after a short finite time interval. Furthermore,
we observe counter-intuitive entanglement rebirth after its sudden death in the
same diamond sample by tuning an experimental parameter, demonstrating that we
can conveniently control the non-Markovianity of the system-environment
coupling through a natural experimental knob. Further tuning of this
experimental knob can make the entanglement dynamics completely coherent under
the same environmental coupling. Probing of entanglement dynamics, apart from
its fundamental interest, may find applications in quantum information
processing through control of the environmental coupling.
