Reversibility of continuous-variable quantum cloning
- Department of Optics, Palacky University, 17. listopadu 50, 77200 Olomouc (Czech Republic)
- Quantum Information and Communication, Ecole Polytechnique, Case Postale 165, Universite Libre de Bruxelles, 1050 Brussels (Belgium)
We analyze a reversibility of optimal Gaussian 1{yields}2 quantum cloning of a coherent state using only local operations on the clones and classical communication between them and propose a feasible experimental test of this feature. Performing Bell-type homodyne measurement on one clone and anticlone, an arbitrary unknown input state (not only a coherent state) can be restored in the other clone by applying appropriate local unitary displacement operation. We generalize this concept to a partial reversal of the cloning using only local operations and classical communication (LOCC) and we show that this procedure converts the symmetric cloner to an asymmetric cloner. Further, we discuss a distributed LOCC reversal in optimal 1{yields}M Gaussian cloning of coherent states which transforms it to optimal 1{yields}M{sup '} cloning for M{sup '}<M. Assuming the quantum cloning as a possible eavesdropping attack on quantum communication link, the reversibility can be utilized to improve the security of the link even after the attack.
- OSTI ID:
- 20640594
- Journal Information:
- Physical Review. A, Vol. 69, Issue 1; Other Information: DOI: 10.1103/PhysRevA.69.012314; (c) 2004 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
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