Hannover 2010 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 25: Quantum Information: Quantum Communication I
Q 25.5: Talk
Wednesday, March 10, 2010, 11:30–11:45, E 214
Displacement Controlled Photon Number Resolving Detector for Optical Coherent States. — •Christoffer Wittmann1,2, Ulrik L. Andersen1,2,3, Masahiro Takeoka4, Denis Sych1,2, and Gerd Leuchs1,2 — 1Max Planck Institute for the Science of Light, Erlangen, Germany — 2Institute for Optics, Information and Photonics, University of Erlangen-Nuremberg, Erlangen, Germany — 3Department of Physics, Technical University of Denmark, Lyngby, Denmark — 4National Institute of Information and Communications Technology (NICT), Tokyo, Japan
Optimal discrimination of non-orthogonal quantum states is one of the fundamental tasks in quantum detection theory. For weak coherent states, the standard detection schemes are not able to achieve error free sensitivity in principle. We propose and experimentally realize a novel detection strategy for the discrimination of two optical coherent states [1]. The scheme is then extended for probabilistic discrimination by accepting also inconclusive measurement outcomes. We show that our discrimination strategy based on an optimized displacement and a photon number resolving measurement, allows for smaller error rates than the homodyne strategy [2] and demonstrate this experimentally [3]. [1] C. Wittmann et al., Phys. Rev. Lett. 101, 210501 (2008) ; [2] C. Wittmann et al., Jour. Mod. Opt., published online (arXiv:0905.2496v1 [quant-ph]), (2009); [3] C. Wittmann et al., arXiv:0906.2859 [quant-ph], (2009).