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HL: Halbleiterphysik

HL 21: Photonische Kristalle

HL 21.5: Vortrag

Dienstag, 27. März 2001, 16:30–16:45, S9/10

Theory of van-der-Waals forces in photonic crystals — •Kurt Busch¹ and Vanik Mkrtchian² — ¹Institut für Theorie der Kondensierten Materie, Universität Karlsruhe, 76128 Karlsruhe — ²Institute for Physical Research, Armenian Academy of Sciences, Ashtarak, Armenia

Any alteration of the fundamental force of electromagnetism will have observable consequences in atomic and molecular quantum electrodynamics.

Photonic crystals represent a novel class of optical materials with which such an alteration of the electromagnetic spectrum can be achieved in a controlled fashion.
We present a theory of the van-der-Waals interaction between two atoms for arbitrary isotropic dispersion relation. As an application, we

consider the case of identical two-level atoms with a transition frequency inside a photonic band gap, i.e., a situation where the atoms are located inside the air regions of a photonic crystal that exhibits a complete photonic band gap. We show, that for atomic separations of the order of the transition wavelength and transition frequencies below or above the center of the gap, the van-der-Waals interaction may be strongly enhanced or suppresed relative to its vacuum value. This may have important consequences for adhesive forces in certain self-organizing colloidal suspensions.