1999/11/30 by Anthony Chefles
Computer Science · Physics and Astronomy · #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum algorithm #Quantum operation #Quantum state #Set (abstract data type) #State (computer science) #Superposition principle #Unitary state #Unitary transformation #quant-ph
paper · pdf · doi:10.1016/s0375-9601(00)00291-7
Minor cosmetic changes
arxiv created 2000/03/07 · openalex publication_date 2000/05/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We derive a necessary condition for the existence of a completely-positive, linear, trace-preserving map which deterministically transforms one finite set of pure quantum states into another. This condition is also sufficient for linearly-independent initial states. We also examine the issue of quantum coherence, that is, when such operations maintain the purity of superpositions. If, in any deterministic transformation from one linearly-independent set to another, even a single, complete superposition of the initial states maintains its purity, the initial and final states are related by a unitary transformation.