  Noise is the main obstacle for the realization of fault tolerant quantum
information processing and secure communication over long distances. In this
work, we propose a communication protocol relying on simple linear optics that
optimally protects quantum states from non-Markovian or corre- lated noise. We
implement the protocol experimentally and demonstrate the near ideal protection
of coherent and entangled states in an extremely noisy channel. Since all
real-life channels are exhibit- ing pronounced non-Markovian behavior, the
proposed protocol will have immediate implications in improving the performance
of various quantum information protocols.
