corner
corner

Phys. Rev. A 71, 042332 (2005) [10 pages]

Optimal copying of entangled two-qubit states

Download: PDF (125 kB) Buy this article Export: BibTeX or EndNote (RIS)

J. Novotný1, G. Alber2, and I. Jex1
1Department of Physics, FJFI ČVUT, Břehová 7, 115 19 Praha 1-Staré Město, Czech Republic
2Institut für Angewandte Physik, Technische Universität Darmstadt, D-64289 Darmstadt, Germany

Received 23 October 2004; published 21 April 2005

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.

© 2005 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevA.71.042332
DOI:
10.1103/PhysRevA.71.042332
PACS:
03.67.Mn, 03.65.Ud