1998/05/22 by A. E. Allahverdyan, Allahverdyan, A. E., David B. Saakian +2 · 1 citation
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum Physics (quant-ph) #quant-ph
paper · pdf · doi:10.48550/arxiv.quant-ph/9805067
LaTex file, 8 pages
arxiv created 1998/05/22 · openalex publication_date 1998/05/22 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
It is well known that quantum theory forbids the exact copying of an unknown quantum state. Therefore in broadcasting of classical information by a quantum channel an additional contribution to the error in the decoding is expected. We consider the optimal copying transformation which is adapted to classical information transmission by two linearly independent quantum states, and show that there is no additional contribution to the error. Instead the clones are correlated, and this breaks their usefulness: The entanglement increases with non-orthogonality of the states. The capacity of the corresponding quantum channel is considered also.