QUASI-OSCILLATORY CASIMIR FORCES

摘要

We consider the interaction of a small metal sphere with an interface. Both the material in the sphere and that in the interface are described by a Drude model dielectric function. In the limit that the plasma frequency for the interface is much larger than that for the sphere, we recover a previous result for a perfectly reflecting interface. In the case that the size of the sphere is much smaller than the plasma wavelength of its material, we find that the force is alternately attractive and repulsive as a function of the distance from the interface. It should be possible to cancel the force of gravity and hence levitate small spheres by means of this effect. The enhanced Casimir force can be interpreted as a modification of the spectrum of vacuum fluctuations which contribute to the force. The effect is large enough that an experimental test should be possible.