Coherent spin precession in normal Fermi liquids

In the collisionless limit the Fermi liquid interaction gives rise to nondissipative spin currents. Due to these currents, a coherently precessing spin state may be formed in NMR-experiments with normal Fermi liquids. This state consists of two domains separated by a coherently precessing domain wall. In one of the domains the magnetization is oriented along, and in the other opposite, to the direction of the magnetic field. Such a state has been studied in NMR-experiments in liquid³He and³He-⁴He solutions. The conditions necessary for the formation of the state are considered. Possible other substances in which similar states may be observed are discussed.