Hannover 2010 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 23: Quantum Effects: Light Scattering and Propagation II / QED I
Q 23.2: Vortrag
Mittwoch, 10. März 2010, 11:00–11:15, A 320
Casimir force on amplifying bodies — •Agnes Sambale1, Dirk-Gunnar Welsch1, and Stefan Yoshi Buhmann2 — 1Theoretisch-Physikalisches Institut, F.-Schiller-Universität Jena, Germany — 2Blacket Laboratory, Imperial College London, United Kingdom
Although most studies on the Casimir forces have so far assumed absorbing bodies, it has recently been realized that besides importance in fundamental research, dispersion forces on amplifying (meta)materials can lead to far-reaching applications. For instance, amplifying media may enhance the influence of left-handed material properties or even lead to repulsive forces.
Within the framework of macroscopic quantum electrodynamics in arbitrary linear media and Lorentz force approach, we present a formula for the Casimir force acting on an amplifying, locally responding, and isotropic polarisable body (Phys. Rev. A 80, 051801(R), 2009). We show that the force can be decomposed into a resonant part arising from emission processes and an off-resonant part looking formally the same as for a purely absorbing medium. We demonstrate that the Casimir force on a weakly polarisable (partially) amplifying body in a purely absorbing environment can be expressed as a sum over the Casimir--Polder forces on the excited atoms the body consists of. This result reveals the common (microscopic) origin of dispersion forces even for excited systems.