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 or repulsive interactions in mesoscopic systems. This is illustrated in two physical situations: (ⅰ) a normal-superconducting junction where the spin-current noise is found to be zero, and (ⅱ) a single-electron transistor where the spin-current noise is found to be Poissonian. Repulsive interactions may also lead to weak attractive correlations (bunching of opposite spins) in conditions far from equilibrium. Spin-current shot noise can also be used to measure the spin relaxation time T_1, and a setup is proposed in a quantum dot geometry.