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Q: Fachverband Quantenoptik und Photonik

Q 54: Quantum Effects: QED

Q 54.6: Vortrag

Donnerstag, 17. März 2011, 15:45–16:00, SCH A01

Feynman diagrams for dispersion interactions — •Harald Haakh, Juergen Schiefele, and Carsten Henkel — Institut für Physik und Astronomie, Universität Potsdam, Germany

Diagrammatic techniques have been used for a long time in perturbative calculations of dispersion interactions between atoms or molecules such as the Casimir-Polder or van-der-Waals interaction [1] and atomic (or molecular) QED, as in the Lamb shift and the calculation of radiative lifetimes. Using the multipolar coupling scheme and Feynman-ordered diagrams rather than retarded graphs, significantly reduces the number of graphs required for calculating the T-matrix. The formalism presented in Ref. [2] offers a rich toolbox that can be applied to different situations reaching from few-body interactions to Bose-Einstein condensates. It is possible to include macroscopic bodies and atomic wave packets, relevant for quantum gases in modern microtraps. Interesting applications involve entangled states or systems out of thermal equilibrium. Resonant contributions arise from the interaction of excited molecules and are supposed to play an important role in molecular biology [3].
[1] D.P. Craig and T. Thirunamachandran, Molecular Quantum Electrodynamics (Dover, 1998)
[2] J. Schiefele and C. Henkel, Phys. Rev. A 82, 023605 (2010),
J. Schiefele and C. Henkel, Phys. Lett. A (2010),
doi:10.1016/j.physleta.2010.11.058, arXiv:1011.4428,
[3] H. Fröhlich, Proc. Nat. Acad. Sci. USA 72, 4211 (1975).