Spin current as a probe of interactions in mesoscopic systems
  The spin resolved current shot noise can uniquely probe the interactions in mesoscopic systems: i) in a normal-superconducting junction, the spin current noise is zero, as carried by singlets, and ii) in a single electron transistor (SET) in the sequential regime, the spin current noise is Poissonian. Coulomb interactions lead to usually repulsive, but also attractive correlations. Spin current shot noise can also be used to measure the spin relaxation time $T_1$. 
Olivier Sauret and Denis Feinberg