München 2004 – wissenschaftliches Programm
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Q: Quantenoptik und Photonik
Q 41: Quanteneffekte III
Q 41.1: Gruppenbericht
Donnerstag, 25. März 2004, 16:30–17:00, HS 218
Dynamical theory of Casimir-Polder forces on excited atoms — •Stefan Yoshi Buhmann1, Ho Trung Dung1,2, Dirk-Gunnar Welsch1, and Ludwig Knöll1 — 1Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany — 2Institute of Physics, National Center for Sciences and Technology, 1 Mac Dinh Chi Street, District 1, Ho Chi Minh city, Vietnam
Based on macroscopic quantum electrodynamics, a dynamical theory of the Casimir-Polder force acting on an excited atomic system near an arbitrary arrangement of dispersing and absorbing magnetodielectric bodies is presented. It is shown that in the weak-coupling regime the total force as a function of time is a superposition of force components that are related to the atomic density matrix elements at chosen time. In particular, it is found that when the atomic system is initially prepared in a coherent superposition of energy eigenstates, then temporally oscillating force components are observed, which is in stark contrast to the case of incoherent state preparation. Finally, it is shown that even the Casimir-Polder force observed after de-excitation of the atomic system is not exactly derivable from a potential, because of the position dependence of the atomic polarizability.