  Quantum teleportation strikingly underlines the peculiar features of the
quantum world. We present an experimental proof of its quantum nature,
teleporting an entangled photon with such high quality that the nonlocal
quantum correlations with its original partner photon are preserved. This
procedure is also known as entanglement swapping. The nonlocality is confirmed
by observing a violation of Bell's inequality by 4.5 standard deviations. Thus,
by demonstrating quantum nonlocality for photons that never interacted our
results directly confirm the quantum nature of teleportation.
