  By investigating the quantum properties of magnetically trapped nS Rydberg
atoms, it is demonstrated that the composite nature of Rydberg atoms
significantly alters their trapping properties opposed to point-like particles
with the same magnetic moment. We show how the specific signatures of the
Rydberg trapping potential can be probed by means of ground state atoms that
are off-resonantly coupled to the Rydberg state via a two photon laser
transition. In addition, it is demonstrated how this approach provides new
possibilities for generating traps for ground state atoms. Simulated
time-of-flight pictures mirroring the experimental situation are provided.
