Improving the Fidelity of Quantum Cloning by Fast Cycling away the Unwanted Transition

Abstract

The fidelity of quantum cloning is very often limited by the accompanying unwanted transitions. We show how the fidelity can be improved by using a coherent field to cycle away the unwanted transitions. We demonstrate this explicitly in the context of the model of Simon {\it et al.} [J. Mod. Opt. {\bf 47}, 233 (2000) ; Phys. Rev. Lett. {\bf 84}, 2993 (2000)]. We also investigate the effects of the number of atoms on the quality of quantum cloning. We show that the universality of the scheme can be maintained by choosing the cycling field according to the input state of the qubit.

RevTeX, 12 pages, 6 figures, the text has been thoroughly revised with modified abstract, new figures and added reference ; resubmitted to Phys. Rev. A

References in corpus (5)

• Trapping of single atoms in cavity QED
• Universal cloning of continuous quantum variables
• Optimal Quantum Cloning via Stimulated Emission
• Optimal N-to-M Cloning of Quantum Coherent States
• Lambda's, V's and optimal cloning with stimulated emission

Cited by in corpus (2)

• Quantum Cloning Machines and the Applications
• A Physical Perspective on Classical Cloning