Solid sup (3)He: Novel magnetic properties of a quantum solid.

Nuclear magnetic ordering in solid sup (3)He provides the ultra- low temperature physicist with a unique opportunity to study cooperative magnetic in a quantum spin system. There are two known, and very different magnetic phases of low density solid sup (3)He, and a higher densities it is believed ferromagnetism exists. With ordering temperatures near lmK, these systems are easily accessible with modern demagnetization cryostats. It is expected that over the next few years experimental and theoretical studies of these systems will result in important advances in our understanding of nuclear magnetism.