Usefulness of classical communication for local cloning of entangled states

Journal Article · Wed Mar 15 00:00:00 EST 2006 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.73.0· OSTI ID:20786862

Demkowicz-Dobrzanski, Rafal ^[1]; Lewenstein, Maciej ^[2]; Sen, Aditi; Sen, Ujjwal ^[3]; Bruss, Dagmar ^[4]

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1. Center for Theoretical Physics, Polish Academy of Sciences Aleja Lotnikow 32/44, 02-668 Warsaw (Poland)
2. ICREA and ICFO-Institut de Ciencies Fotoniques, E-08860 Castelldefels, Barcelona (Spain)
3. Institut fuer Theoretische Physik, Universitaet Hannover, D-30167 Hannover (Germany)
4. Institut fuer Theoretische Physik III, Heinrich-Heine-Universitaet Duesseldorf, 40225 Duesseldorf (Germany)

We solve the problem of the optimal cloning of pure entangled two-qubit states with a fixed degree of entanglement using local operations and classical communication. We show that, amazingly, classical communication between the parties can improve the fidelity of local cloning if and only if the initial entanglement is higher than a certain critical value. It is completely useless for weakly entangled states. We also show that bound entangled states with positive partial transpose are not useful as a resource to improve the best local cloning fidelity.

• OSTI ID: 20786862
• Journal Information: Physical Review. A, Vol. 73, Issue 3; Other Information: DOI: 10.1103/PhysRevA.73.032313; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
DATA TRANSMISSION
ENERGY LEVELS
QUANTUM ENTANGLEMENT
QUANTUM MECHANICS
QUBITS