  Versatile methods for the manipulation of individual quantum systems, such as
confined particles, have become central elements in current developments in
precision spectroscopy, frequency standards, quantum information processing,
quantum simulation, and alike. For atomic and some subatomic particles, both
neutral and charged, a precise control of magnetic fields is essen- tial. In
this paper, we discuss possibilities for the creation of specific magnetic
field configurations which find appli- cation in these areas. In particular, we
pursue the idea of a magnetic bottle which can be switched on and off by
transition between the normal and the superconducting phase of a suitable
material in cryogenic environments, for example in trap experiments in moderate
magnetic fields. Methods for a fine-tuning of the magnetic field and its linear
and quadratic components in a trap are presented together with possible
applications.
