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A: Fachverband Atomphysik
A 17: Attosecond Physics (jointly with Q)
A 17.4: Vortrag
Mittwoch, 21. März 2007, 15:00–15:15, 6G
Attosecond scattering of particles from quantum correlated condensed systems — •Chariton Aris C.-Dreismann — Institut für Chemie, TU Berlin, Sekr. C2, 10623 Berlin
Nuclei and electrons in condensed matter are usually entangled, due to the electromagnetic interaction. However, strong couplings with the "environment" cause an ultrafast decoherence, thus making entaglement effects not accessible to experiments. Recently, neutron [1a] and electron [1b,2] Compton scattering experiments from protons (H-atoms) in several condensed systems at room temperature demonstrated a striking effect, i.e. an "anomalous" decrease of scattering intensity. Due to the large energy (several eV) and momentum (20- 200 Å−1) transfers of these experiments, is the collisional (or scattering) time between the probe particle and the proton 100 − 1000 as. The considered effect, which has no interpretation within conventional neutron scattering theory, is caused by the non-unitary quantum dynamics (due to decoherence) during the ultrashort, but finite, time-window of the scattering process. Examples of experimental results will be shown, and a theoretical outline "from first principles" [3] will be presented.
[1] C. A. C.-Dreismann et al., (a) Phys. Rev. Lett. 79, 2839 (1997); (b) Phys. Rev. Lett. 91, 057403 (2003). [2] Physics Today, p. 9,(Sept. 2003). [3] C. A. C.-Dreismann and S. Stenholm, in preparation.