Erlangen 2018 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 31: Quantum Effects (QED)
Q 31.4: Vortrag
Dienstag, 6. März 2018, 14:45–15:00, K 1.013
Dispersion forces in multi-layered media — •Johannes Fiedler1,2 and Stefan Y. Buhmann1,3 — 1Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany — 2Centre for Materials Science and Nanotechnology, Department of Physics, University of Oslo, Oslo, Norway — 3Freiburg Institute for Advanced Studies, Universität Freiburg, Freiburg, Germany
Dispersion forces are a result of the zero-point fluctuations of the electromagnetic field and are typically attractive for ground-state particles [1]. However, the presence of a medium environment allows for repulsion depending on the optical densities in the particular system. We present a method describing dispersion forces in planar multi-layered systems with continuous dielectric profile and illustrate the impact on Casimir and van der Waals forces with respect to the shape of the inhomogeneity [2]. For particles embedded in a medium we assume a cavity surrounding the particles to account for the impact of Pauli repulsion [3]. A combination of both methods can be applied to nano-sized ice particles below the ocean’s surface. In this situation one finds a repulsive force with respect to the surface that prevents the particle from passing through the surface [4]. Depending on their size the particles levitate at specific distances to the surface due to the balance of buoyancy, Casimir-Polder and salt forces. Further, we illustrate the possibility of capturing methane in thin water layers surrounding ice.
[1] S.Y. Buhmann, Dispersion forces I (Springer Heidelberg, 2012). [2] J. Fiedler et al., in preparation. [3] J. Fiedler et al., J. Phys. Chem. A in press (2017), arXiv: 1710.04945. [4] P. Thiyam et al., in preparation.