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Q: Quantenoptik und Photonik

Q 45: Quanteneffekte III

Q 45.2: Vortrag

Dienstag, 8. März 2005, 14:45–15:00, HU 1072

Repulsive Casimir forces on the nanoscale: limits and feasibility — •Carsten Henkel¹ and Karl Joulain² — ¹Potsdam University, Germany — ²ENSMA Poitiers, France

Casimir forces are becoming increasingly important, as mechanical devices are downscaled into the nanometer range. In particular, serious dysfunction may arise when mobile parts of nano-mechanical systems attract each other and stick together. To cure this problem, it has been suggested that suitable materials (simultaneously dielectric and permeable) may turn the Casimir interaction into repulsion [1]. We establish here fundamental and realistic limits to this approach, taking into account material dispersion with simple models [2]. The theory is generalized to planar, multilayer mirrors at finite temperature. We show that repulsion in the nanometer range is extremely difficult to achieve because typical permeable materials do not have a sufficiently large magnetic response. Even recently proposed metamaterials are not suitable because of the breakdown of the effective medium approximation.

[1] O. Kenneth, I. Klich, A. Mann, and M. Revzen, Phys. Rev. Lett. 89 (2002) 033001.

[2] C. Henkel and K. Joulain, quant-ph/0407153; C. Raabe and D. G. Welsch, quant-ph/0408075; M. S. Tomaš, quant-ph/041057.