Electron--Electron Scattering in Quantum Wires and it's Possible Suppression due to Spin Effects

A microscopic picture of electron-electron pair scattering in single mode quantum wires is introduced which includes electron spin. A new source of `excess' noise for hot carriers is presented. We show that zero magnetic field `spin' splitting in quantum wires can lead to a dramatic `spin'-subband dependence of electron--electron scattering, including the possibility of strong suppression. As a consequence extremely long electron coherence lengths and new spin-related phenomena are predicted. Since electron bands in III-V semiconductor quantum wires are in general spin-split in zero applied magnetic field, these new transport effects are of general importance.