Spin Gunn Effect

TL;DR

This paper predicts a novel effect where unpolarized current in certain semiconductors spontaneously forms spin-polarized pulses at high electric fields without needing magnetic fields, driven by conductivity differences.

Contribution

It introduces the concept of the Spin Gunn Effect, a new mechanism for generating spin-polarized currents in electron-doped semiconductors at room temperature.

Findings

Unpolarized current becomes unstable at high electric fields in GaAs and InP.

Spin-polarized current pulses form spontaneously without spin-orbit interaction.

Magnetic fields are not necessary but can align pulse polarization.

Abstract

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.