Joint measurements on qubits and cloning of observables

Alessandro Ferraro*, Matteo G. A. Paris

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)


Cloning of observables, unlike standard cloning of states, aims at copying the information encoded in the statistics of a class of observables rather then on quantum states themselves. In such a process the emphasis is on the quantum operation (evolution plus measurement) necessary to retrieve the original information. We analyze, for qubit systems, the cloning of a class generated by two noncommuting observables, elucidating the relationship between such a process and joint measurements. This helps in establishing an optimality criterion for cloning of observables. We see that, even if the cloning machine is designed to act on the whole class generated by two noncommuting observables, the same optimal performances of a joint measurement can be attained. Finally, the connection with state dependent cloning is enlightened.

Original languageEnglish
Pages (from-to)149-157
Number of pages9
JournalOpen systems & information dynamics
Issue number2
Publication statusPublished - Jun 2007
EventInternational Conference on New Trends in Quantum Mechanics, Fundamental Aspects and Applications - Palermo, Italy
Duration: 11 Nov 200513 Nov 2005



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