Cloning of continuous quantum variables
The cloning of quantum variables with continuous spectra is analyzed. A Gaussian quantum cloning machine is exhibited that copies equally well the states of two conjugate variables such as position and momentum. It also duplicates all coherent states with a fidelity of 2/3. More generally, the copies are shown to obey a no-cloning Heisenberg-like uncertainty relation.
Cerf
NJ
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, USA.
Ipe
A
Rottenberg
X