Spin-current shot noise in spin transitors

In this paper, we derive a general expression for the zero-frequency-limit spin-current shot noise in spin transistors. We find that the noise in one lead is caused by spin-resolved transmissions from the other lead to this lead and the interferences of these transmissions. Our numerical results demonstrate that the spin-current shot noise will change periodically with the channel length, and oscillate with the spin-momentum interaction coefficient. Besides, it will become saturated for large source-drain bias. The knowledge we gain from this study will help researchers to evaluate the spin-current shot noise in the future spintronic devices. ? 2006 IEEE.EI