  We show that by magnetically trapping a superconducting microsphere close to
a quantum circuit, it is experimentally feasible to perform ground-state
cooling and to prepare quantum superpositions of the center-of-mass motion of
the microsphere. Due to the absence of clamping losses and time dependent
electromagnetic fields, the mechanical motion of micrometer-sized metallic
spheres in the Meissner state is predicted to be very well isolated from the
environment. Hence, we propose to combine the technology of magnetic microtraps
and superconducting qubits to bring relatively large objects to the quantum
regime.
