We predict that the flow of unpolarized current in electron-doped GaAs and InP at room temperature is unstable at high electric fields to the dynamic formation of spin-polarized current pulses. Spin-polarized current is spontaneously generated because the conductivity of a spin-polarized electron gas differs from that of an unpolarized electron gas, even in the absence of spin-orbit interaction. Magnetic fields are not required for the generation of these spin-polarized current pulses, although they can help align the polarization of sequential pulses along the same axis.
@article{arxiv.cond-mat/0407547,
title = {Spin Gunn Effect},
author = {Yunong Qi and Zhi-Gang Yu and Michael E. Flatté},
journal= {arXiv preprint arXiv:cond-mat/0407547},
year = {2007}
}