Spin current as a probe of interactions in mesoscopic systems

TL;DR

This paper demonstrates how spin current shot noise measurements can reveal interaction effects, correlations, and spin relaxation times in mesoscopic systems like normal-superconducting junctions and single electron transistors.

Contribution

It introduces the use of spin current shot noise as a novel probe for interactions and spin relaxation in mesoscopic systems.

Findings

Spin current noise is zero in normal-superconducting junctions.

Spin current noise is Poissonian in single electron transistors.

Spin shot noise can measure spin relaxation time T1.

Abstract

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 $T_1$.