Hamburg 2009 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 5: Quanteninformation: Konzepte I
Q 5.1: Talk
Monday, March 2, 2009, 10:45–11:00, VMP 6 HS-D
Copies with high fidelity from a simple quantum cloning machine — •Michael Siomau1 and Stephan Fritzsche1,2,3 — 1Max-Planck-Institut für Kernphysik, Postfach 103980, D-69117 Heidelberg, Germany — 2Gesellschaft für Schwerionenforschung, D-64291 Darmstadt, Germany — 3Frankfurt Institute for Advanced Studies, D-60438 Frankfurt am Main, Germany
We investigate theoretically a symmetric quantum cloning machine (QCM) which provides two identical copies for any given input qubit. When compared with the Universal QCM [1], that produces copies with constant fidelity F=5/6≈ 0.83 for any given input state, and the Equatorial QCM [2] (copies with fidelity F≈ 0.85 for states on the equator of the Bloch sphere), our suggested scheme produces copies with fidelity 0.95≥ F≥ 0.90 for some selected region of the Bloch sphere. The properties of the new transformation are discussed along with possible applications of this scheme.
[1] V. Bužek and M. Hillery, Phys.Rev.A. 54, 1844 (1996)
[2] D. Bruß, M. Cinchetti, G.M. D‘Ariano and C. Macchiavell, Phys.Rew.A 62, 012302 (2000)