1997/05/12 by L.-M. Duan, Lu-Ming Duan, Guang-Can Guo +3
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/9705018
9 pages, no figures, Latex
arxiv created 1997/05/12 · openalex publication_date 1997/05/12 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A fundamental question in quantum mechanics is, whether it is possible to replicate an arbitrary unknown quantum state. Then famous quantum no-cloning theorem [Nature 299, 802 (1982)] says no to the question. But it leaves open the following question: If the state is not arbitrary, but secretly chosen from a certain set $= | Ψ1> ,| Ψ2> ,... ,| Ψn> , whether is the cloning possible? This question is of great practical significance because of its applications in quantum information theory. If the states | Ψ1>, | Ψ2>,... and | Ψn> are linearly-dependent, similar to the proof of the no-cloning theorem, the linearity of quantum mechanics forbids such replication. In this paper, we show that, if the states | Ψ1>, | Ψ2>, ... and | Ψn> are linearly-independent, they do can be cloned by a unitary-reduction process.