title: Pauli cloning of a quantum Bit
abstract: A family of asymmetric quantum cloning machines is introduced that produce two approximate copies of a single quantum bit, each copy emerging from a Pauli channel. A no-cloning inequality is derived, describing the balance between the quality of the copies. The Pauli cloning machine is also shown to put a limit on the quantum capacity of Pauli channels.
authors.affiliation: Ecole Polytechnique, CP 165, Universite Libre de Bruxelles, 1050 Brussels, Belgium and Information and Computing Technologies Research Section, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 and W.
authors.initials: NJ
authors.lastname: Cerf