Spin current shot noise as a probe of interactions in mesoscopic systems

摘要

It is shown that the spin resolved current shot noise can probe attractive orrepulsive interactions in mesoscopic systems. This is illustrated in twophysical situations : i) a normal-superconducting junction where the spincurrent noise is found to be zero, and ii) a single electron transistor (SET),where the spin current noise is found to be Poissonian. Repulsive interactionsmay also lead to weak attractive correlations (bunching of opposite spins) inconditions far from equilibrium. Spin current shot noise can be used to measurethe spin relaxation time $T_1$, and a set-up is proposed in a quantum dotgeometry.