Lifshitz-type formulas for the free energy and Casimir-Polder force between an atom possessing a permanent magnetic moment and a wall made of different materials are derived. A simple model allowing analytical results is considered where the atomic magnetic susceptibility is frequency independent and the wall is made of an ideal metal. Numerical computations of the Casimir-Polder force are performed for the cases of a H atom interacting with walls made of an ideal metal, a nonmagnetic metal (Au), a ferromagnetic metal (Fe), and a ferromagnetic dielectric. It is shown that for the first three wall materials inclusion of the atomic magnetic moment decreases the magnitude of the Casimir-Polder force, while for the fourth material the force increases.

• Received 19 February 2009

DOI:https://doi.org/10.1103/PhysRevA.79.042906