Magnetic-tip trap system

Abstract

We report a detailed theoretical model of a recently demonstrated magnetic trap system based on a pair of magnetic tips. The model takes into account key parameters such as tip diameter, facet angle, and gap separation. It yields quantitative descriptions consistent with experiments such as the vertical and radial frequency, equilibrium position, and the optimum facet angle that produces the strongest confinement. We arrive at the striking conclusion that a maximum confinement enhancement can be achieved at an optimum facet angle θmax=arccos2/3. We also discuss a critical gap which is the maximum gap between the tips for the confinement enhancement effect to occur. This magnetic trap and its theoretical model serve as an interesting example of a simple and elementary magnetic trap in physics.