Berlin 2005 – wissenschaftliches Programm

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K: Kurzzeitphysik

K 5: Neue Verfahren / Hochdruckphysik

K 5.1: Vortrag

Mittwoch, 9. März 2005, 11:00–11:20, HU 3092

Attosecond entanglement of protons and electrons in molecular hydrogen - Experimental results and theoretical considerations — •C. Aris C.-Dreismann¹, Tyno Abdul-Redah², and Maciej Krzystyniak¹ — ¹Inst. f. Chemie, Stranski Lab., TU Berlin, D-10623 Berlin — ²ISIS Facility, R.A.L., Oxfordshire, OX11 0QX, U.K.

Several experiments on liquid and solid samples containing protons show a striking shortfall in the intensity of epithermal neutrons scattered by the protons [1-3]. E.g., neutrons colliding with water for just attoseconds (as) will see a ratio of H to O of roughly 1.5 to 1, instead of 2 to 1 [1,3]. In our neutron Compton scattering (NCS) experiments, the duration of a neutron-proton scattering event is about 50-500 as. Recently this effect has been confirmed using electron-proton Compton scattering (ECS) from a solid polymer [2,3]. Electrons and neutrons interact with protons via fundamentally different forces – electromagnetic and strong. Theoretical considerations support the presence of attosecond quantum entanglement in the dynamics of the protons and the surrounding electrons. New NCS experiments on liquid hydrogen (H2, D2, and HD; T = 20 K) demonstrate that spin-entanglement between two protons play no role in this effect. Our results indicate that hitherto unknown features of attosecond dynamics of chemical bonds may become accessible to attosecond scattering techniques.

[1] C. A. Chatzidimitriou-Dreismann et al., Phys. Rev. Lett. 79, 2839 (1997). [2] C. A. Chatzidimitriou-Dreismann et al. Phys. Rev. Lett. 91, 057403 (2003). [3] Cf.: Physics Today, sect. ’Physics Update’, p. 9, Sept. 2003; Physik in unserer Zeit 35(4), 174 (2004).