We investigate the time-dependent fluctuations of the electric current injected from a reservoir with a non-equilibrium spin accumulation into a mesoscopic conductor. We show how the current noise power directly reflects the magnitude of the spin accumulation in two easily noticeable ways. First, as the temperature is lowered, the small-bias noise saturates at a value determined by the spin accumulation. Second, in the presence of spin-orbit interactions in the conductor, the current noise exhibits a sample-dependent mesoscopic asymmetry under reversal of the electric current direction. These features provide for a purely electric protocol for measuring spin accumulations.
@article{arxiv.1104.2353,
title = {Measuring Spin Accumulations with Current Noise},
author = {Jonathan Meair and Peter Stano and Philippe Jacquod},
journal= {arXiv preprint arXiv:1104.2353},
year = {2011}
}