corner
corner

Phys. Rev. A 68, 054301 (2003) [4 pages]

Quantum cloning of mixed states in symmetric subspaces

Download: PDF (58 kB) Buy this article Export: BibTeX or EndNote (RIS)

Heng Fan
Quantum Computation and Information Project, ERATO, Japan Science and Technology Corporation, Daini Hongo White Building 201, Hongo 5-28-3, Bunkyo-ku, Tokyo 113-0033, Japan

Received 1 May 2003; published 3 November 2003

Quantum-cloning machine for arbitrary mixed states in symmetric subspaces is proposed. This quantum-cloning machine can be used to copy part of the output state of another quantum-cloning machine and is useful in quantum computation and quantum information. The shrinking factor of this quantum cloning achieves the well-known upper bound. When the input is identical pure states, two different fidelities of this cloning machine are optimal.

© 2003 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevA.68.054301
DOI:
10.1103/PhysRevA.68.054301
PACS:
03.67.-a, 03.65.Ta, 89.70.+c