Optimal copying of entangled two-qubit states

2004/11/15 by J. Novotny, Jaroslav Novotný, G. Alber +2 · 1 citation
Computer Science · Mathematics · Physics and Astronomy · #Computer science #Copying #Fidelity #Law #Mathematics #Physics #Political science #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum entanglement #Quantum mechanics #Qubit #quant-ph

paper · pdf · doi:10.1103/physreva.71.042332

13 pages, 7 figures

arxiv created 2004/11/15 · openalex publication_date 2005/04/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We investigate the problem of copying pure two-qubit states of a given degree of entanglement in an optimal way. Completely positive covariant quantum operations are constructed which maximize the fidelity of the output states with respect to two separable copies. These optimal copying processes hint at the intricate relationship between fundamental laws of quantum theory and entanglement.

Citations

• Entanglement of Formation of an Arbitrary State of Two Qubits
• Pauli Cloning of a Quantum Bit
• A single quantum cannot be cloned
• Entanglement of a Pair of Quantum Bits
• Quantum copying: Beyond the no-cloning theorem
• Quantum cloning of orthogonal qubits
• Distributed Entanglement

Cited by

• Usefulness of classical communication for local cloning of entangled states