Hannover 2010 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
Q: Fachverband Quantenoptik und Photonik
Q 25: Quantum Information: Quantum Communication I
Q 25.4: Talk
Wednesday, March 10, 2010, 11:15–11:30, E 214
Hybrid quantum repeater with imperfect memories — •Nadja Kolb Bernardes1,2 and Peter van Loock1,2 — 1Optical Quantum Information Theory Group, Max Planck Institute for the Science of Light — 2Institute of Theoretical Physics I, Universität Erlangen-Nürnberg
We discuss the efficiency of quantum error correction (QEC) codes for quantum repeaters based on atomic qubit-entanglement distribution through optical coherent-state communication (hybrid quantum repeater [1]). In particular, we consider nonlocal distributions of two-qubit entangled memory pairs based on unambiguous discrimination measurements of coherent states [2]. The conditionally prepared, entangled states will be subject to local memory dephasing, which is to be suppressed by means of QEC codes. For this realistic case of imperfect memories, we explore the regimes in which the encoding pays off and where it does not. Our model gives the minimum requirements on the local memories, unencoded or encoded,in order to outperform direct transmissions or quantum relay approaches.
[1]P. van Loock, T. D. Ladd, K. Sanaka, F. Yamaguchi, Kae Nemoto, W. J. Munro, and Y. Yamamoto, Phys. Rev. Lett. 96, 240501 (2006).
[2]P. van Loock,N. Lütkenhaus, W. J. Munro, Kae Nemoto,Phys. Rev. A 78, 062319 (2008).