  Superconductors are considered in view of applications to atom chip devices.
The main features of magnetic traps based on superconducting wires in the
Meissner and mixed states are discussed. The former state may mainly be
interesting for improved atom optics, while in the latter, cold atoms may
provide a probe of superconductor phenomena. The properties of a magnetic side
guide based on a single superconducting strip wire placed in an external
magnetic field are calculated analytically and numerically. In the mixed state
of type II superconductors, inhomogeneous trapped magnetic flux, relaxation
processes and noise caused by vortex motion are posing specific challenges for
atom trapping.
