Hannover 2013 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 60: Quantum effects: Entanglement and decoherence I
Q 60.1: Group Report
Friday, March 22, 2013, 11:00–11:30, A 310
Energetic consequences of pure decoherence in ultrafast collisions — •C. Aris Dreismann1, Evan MacA. Gray2,3, and Tom P. Blach4 — 1Institute of Chemistry, TU Berlin — 2Griffith University, Brisbane, Australia — 3Queensland Micro- and Nanotechnology Centre — 4Queensland University of Technology, Brisbane, Australia
We consider the dynamics of open quantum systems exhibiting pure decoherence (without disipation) as described by the well known master equations of the so-called Lindblad form. They ensure positivity of the system's reduced density operator, but they also exhibit an unexpected feature: an intrinsic increase of the system's energy [1]. Recently this effect of decoherence has been theoretically shown [2,3] to be of more general character, under the condition that the characteristic time of the process is sufficient short. Here we report first experimental evidence of this surprising effect, in the frame of attosecond neutron Compton scattering (NCS) from protons and deuterons (of gaseous H2 and D2 at 40 K) [4]. Additionally we provide a qualitative theoretical understanding of the experimental results [4]. The observations stand in blatant contradiction to conventional theory, which is based on the Golden Rule and in which quantum correlations [5] and decoherence between probe particle and scatterer play no role.
[1] L. E. Ballentine, Phys. Rev. A 43 (1991) 9. [2] L. S. Schulman and B. Gaveau, Phys. Rev. Lett. 97 (2006) 240405. [3] N. Erez et al., Nature 452 (2008) 724. [4] C. A. C.-Dreismann, E. MacA. Gray and T. P. Blach, AIP Advances 1 (2011) 022118; and Nucl. Instr. Meth. A 676 (2012) 120. [5] K. Modi et al., Rev. Mod. Phys. 84 (2012) 1655.