Novel Magnetic Properties of Solid Helium‐3
Nuclear magnetic ordering in solid helium‐3 provides the ultralow‐temperature physicist with a unique opportunity to study cooperative magnetic phenomena in a quantum spin system. There are two known—and very different— magnetic phases of low‐density solid He3, and at higher densities ferromagnetism may exist. with ordering temperatures at low densities near 1 mK, these systems are easily accessible with modern demagnetization cryostats. Over the next few years experimental and theoretical studies of these systems will advance considerably our understanding of nuclear magnetism.