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Q: Fachverband Quantenoptik und Photonik
Q 44: Quanteneffekte (Interferenz / Sonstige)
Q 44.2: Talk
Thursday, March 13, 2008, 14:15–14:30, 2D
Phase space sub-Planck structures: experimental realization in time-frequency domain — •Ludmila Praxmeyer1, Piotr Wasylczyk2, Czeslaw Radzewicz2, and Krzysztof Wodkiewicz2 — 1Optical Quantum Information Theory Group, Max Planck Research Group, Institute of Optics, Information and Photonics, 91058 Erlangen, Germany — 2Faculty of Physics, Warsaw University, Poland
It was shown by Zurek [1] that sub-Planck structures in phase space play a surprisingly important role in the distinguishability of quantum states. A sub-Planck phase space shift applied to a superposition of coherent states is sufficient to produce a state which is orthogonal to the unshifted one! The effect was originally studied for a superposition of four coherent states [1], then it was shown that superpositions of just two coherent states lead to a similar result [2]. We present experimental data of the frequency resolved optical gating (FROG) measurements of light pulses revealing interference features which correspond to sub-Planck structures in phase space [3]. For superpositions of pulses a small, sub-Fourier shift in the carrier frequency leads to a state orthogonal to the initial one, although in the representation of standard time-frequency distributions these states seem to have a non-vanishing overlap.
[1] W. Zurek, Nature 412, 712 (2001).
[2] L. Praxmeyer, K. Wodkiewicz, Laser Phys. Vol.15, No.10, 1477 (2005); L. Praxmeyer, PhD thesis (2005).
[3] L. Praxmeyer, P. Wasylczyk, Cz. Radzewicz, K. Wodkiewicz, Phys. Rev. Lett. 98, 063901 (2007).