  We consider the energy shift for an atom close to a non-magnetic body with a
magnetic moment coupled to a quantized magnetic field. The corresponding
repulsive Casimir-Polder force is obtained for a perfect conductor, a metal, a
dielectric medium, with dielectric properties modeled by a Drude formula, and a
superconductor at zero temperature. The dielectric properties of the
superconductor is obtained by making use of the Mattis-Bardeen linear response
theory and we present some useful expressions for the low-frequency
conductivity. The quantum dynamics with a given initial state is discussed in
terms of the well-known Weisskopf-Wigner theory and is compared with
corresponding results for a electric dipole coupling. The results obtained are
compatible with a conventional master equation approach. In order to illustrate
the dependence on geometry and material properties, numerical results are
presented for the ground state using a two-level approximation.
