  We describe a proposed experimental search for exotic spin-coupled
interactions using a solid-state paramagnetic insulator. The experiment is
sensitive to the net magnetization induced by the exotic interaction between
the unpaired insulator electrons with a dense, non-magnetic mass in close
proximity. An existing experiment has been used to set limits on the electric
dipole moment of the electron by probing the magnetization induced in a
cryogenic gadolinium gallium garnet sample on application of a strong electric
field. With suitable additions, including a movable source mass, this
experiment can be used to explore "monopole-dipole" forces on polarized
electrons with unique or unprecedented sensitivity. The solid-state,
non-magnetic construction, combined with the low-noise conditions and extremely
sensitive magnetometry available at cryogenic temperatures could lead to a
sensitivity over ten orders of magnitude greater than exiting limits in the
range below 1 mm.
