Geometrical dependence in Casimir-Polder repulsion

Repulsion, induced from quantum vacuum fluctuations, for an anisotropically polarizable atom on the symmetry axis of an anisotropically polarizable annular disk is studied. There exist two torsion-free points on each side of the annular disk, where the interaction energy is orientation independent. The position of the second of the two torsion-free points, on either side of the disk, is shown to determine the orientation dependence of the atom at distances far from the plate, revealing a geometrical dependence. In the ring limit of the annular disk, an additional region of repulsion emerges.

Automated summary

This study explores the repulsion effects on an anisotropically polarizable atom located on the symmetry axis of an anisotropically polarizable annular disk, which has two torsion-free points on each side. The position of the second torsion-free point on either side affects the orientation dependence of the atom, showing a geometrical relationship. In the ring limit of the annular disk, an additional region of repulsion is observed.