Hannover 2010 – wissenschaftliches Programm

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Q: Fachverband Quantenoptik und Photonik

Q 63: Quantum Effects: Entanglement and Decoherence III

Q 63.7: Vortrag

Freitag, 12. März 2010, 15:45–16:00, A 310

Attosecond neutron scattering from open quantum systems — •C. Aris C.-Dreismann — Institute of Chemistry, Technical University of Berlin, D-10623 Berlin, Germany

Neutron Compton scattering (NCS) from single nuclei of atoms in molecules, e.g. H2 (and/or single atoms, e.g. He) is effectuated in the attosecond timescale. The related "scattering time" is considered in detail, in relation with the Uncertainty Relations. It is shown that the entity "scattering time" gives a statistical measure of the length of the time interval during which an elementary neutron-nucleus collision may occur, in the same way that the spatial extent of a particle wavefunction (or wavepacket) gives a statistical measure of the extent of the region in which the particle may be found. Consequently, the elementary neutron-nucleus scattering process represents a time-interference phenomenon over the sub-femtosecond "scattering time" window. Moreover, the very short-range strong interaction of the neutron-nucleus collision implies that the scattering system (e.g. a proton partically "dressed" with electrons) must be considered as an open quantum system. Experimental results from H2, D2 and HD are mentioned and their "anomalous" scattering property [1] in the attosecond timescale is qualitatively discussed, also in connention with the Schulman-Gaveau effect [2].

[1] G. Cooper, A. P. Hitchcock, C. A. Chatzidimitriou-Dreismann, PRL 100, 043204 (2008); and references therein. [2] L. S. Schulman, B. Gaveau, PRL 97, 240405 (2006).