München 2004 – scientific programme
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Q: Quantenoptik und Photonik
Q 45: Quanteninformation IV
Q 45.7: Talk
Friday, March 26, 2004, 12:45–13:00, HS 101
Continuous variable quantum erasing — •Ulrik Andersen1, Olivier Glöckl1, Stefan Lorenz1, Radim Filip2, and Gerd Leuchs1 — 1Institute of Optics, Information and Photonics, Max-Planck Research Group, University of Erlangen-Nuernberg, Staudtstr. 7/B2, D-91058 Erlangen,Germany — 2Department of Optics,Research Center for Optics,Palacky University,17. listopadu 50,77200 Olomouc,Czech Republic
Due to quantum complementarity the perfect measurement of two conjugate variables is not possible. In a double slit experiment, this means that the measurement of the which-way information will destroy the interference information. However, if one manages to erase the which-way information, the interference can be revived [1]. In the continuous variable quantum erasing scheme [2] we consider a Gaussian light state which can be characterized by two conjugate quadrature variables: the amplitude and the phase quadrature. Information retrieval can be obtained by implementing a quantum nondemolition measurement. Performing such a measurement on the amplitude quadrature gives rise to excess noise in the phase quadrature according to Heisenbergs uncertainty relation. However, if the amplitude quadrature is erased, it is possible to revive the phase information by correlating the outputs. The experimental realization of such a scheme is presented. [1] M.O. Scully et al., Nature 351,111 (1991) [2] R. Filip, Phys. Rev. A 67, 42111 (2003)