Lassen, Mikael Østergaard1; Berni, Adriano1; Madsen, Lars Skovgaard1; Filip, Radim4; Andersen, Ulrik Lund1
1 Department of Physics, Technical University of Denmark2 Quantum Physics and Information Techology, Department of Physics, Technical University of Denmark3 Palacky University4 Palacky University
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 correlated 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 exhibiting pronounced non-Markovian behavior, the proposed protocol will have immediate implications in improving the performance of various quantum information protocols.