Acoustic-phonon limited mobility in periodically modulated quantum wires

We investigate acoustic-phonon scattering in quantum wires subject to a periodic potential along the propagating direction. A technique for modeling the electronic structure of the periodic system is introduced using the imaginary time propagation method. The acoustic-phonon scattering rate is evaluated by taking umklapp processes into account. We found umklapp processes can cause a significant increase in intersubband scattering but is negligible for intrasubband scattering. Overall, the exact treatment of the electron dispersion relation improves the acoustic-phonon limited mobility compared to earlier estimates [H. Noguchi, J. P. Leburton, and H. Sakaki, Phys. Rev. B 47, 15593 (1993)].