Persistent spin and mass currents and Aharonov-Casher effect
  Spin-orbit interaction produces persistent spin and mass currents in the ring via the Aharonov-Casher effect. The experiment in $^3He-A_1$ phase, in which this effect leads to the excitation of mass and spin supercurrent is proposed. 
A. V. Balatsky and B. L. Altshuler