2015/04/30 by Bi-Heng Liu, Bi‐Heng Liu, Xiao‐Min Hu +12
Computer Science · Mathematics · Physics and Astronomy · #Artificial intelligence #Coding (social sciences) #Computer science #Concurrence #Markov process #Mathematics #Mutual information #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum channel #Quantum entanglement #Quantum mechanics #Qubit #Statistical physics #Superdense coding #Theoretical computer science #quant-ph
paper · pdf · doi:10.1209/0295-5075/114/10005
published as EPL (Europhysics Letters) 114, 10005 (2016) · 6 pages, 4 figures. V2: Minor changes
openalex publication_date 2016/04/01 · arxiv created 2016/04/28 · arxiv updated 2016/05/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Many quantum information tasks rely on entanglement, which is used as a resource, for example, to enable efficient and secure communication. Typically, noise, accompanied by loss of entanglement, reduces the efficiency of quantum protocols. We develop and demonstrate experimentally a superdense coding scheme with noise, where the decrease of entanglement in Alice's encoding state does not reduce the efficiency of the information transmission. Having an almost fully dephased classical two-photon polarization state at the time of encoding with concurrence of , we reach values of mutual information close to with 3-state (4-state) encoding. This high efficiency relies both on non-Markovian features, that Bob exploits just before his Bell state measurement, and on very high visibility of the Hong-Ou-Mandel interference within the experimental set-up. Our proof-of-principle results with measurements on mutual information pave the way for exploiting non-Markovianity to improve the efficiency and security of quantum information processing tasks.