The basic property of superfluidity is the existence of mass currents that do not dissipate energy. In addition to that property, the superfluid phases of 3He also support dissipationless spin currents, i.e. spins pointing up flow in opposite direction than spins pointing down. In 3He-B the spin currents are determined by a spin-orbit rotation axis n(r), which generally depends on the location r. The purpose of the hydrostatic theory is to calculate the field n(r), also known as texture. The texture can be measured by NMR, and thus the theory can be compared to experiments. An important part of the project is to extract those parameters from experiments that cannot reliably be calculated theoretically. Knowledge of the texture is essential for understanding many phenomena: vortices, 3He in aerogel, Josephson phenomena etc.
Back to helium theory page29.3.2001, Erkki Thuneberg, Email