Effects of a magnetic field on electron-phonon scattering in quantum wires

We have rigorously calculated the bare electron-phonon scattering rates in semiconductor quantum wires in the presence of an external magnetic field. The magnetic field has several interesting effects on the scattering rates. It drastically reduces acoustic-phonon scattering (by orders of magnitude at easily achievable field strengths), but increases longitudinal-optical and surface optical-phonon scattering. It also enhances the difference between the acoustic-phonon scattering rates at energies just below and above a subband minimum. The latter effect may cause negative differential mobility to appear in quantum wires at electric fields far below the threshold for intervalley transfer.