NONLINEAR TRANSPORT IN QUASI-2-DIMENSIONAL SYSTEMS DRIVEN BY INTENSE TERAHERTZ FIELDS

A fully nonlinear theoretical study is carried out on electron transpo rt in GaAs-based quasi-two-dimensional systems driven by an intense os cillatory electric field of terahertz (THz) frequency. We consider the role of the two lowest subbands with accurate treatment of intrasubba nd and intersubband impurity, acoustic phonon, and. polar optic-phonon scatterings. The steady oscillating response of the drift velocity an d the electron temperature are obtained by directly solving the time-d ependent momentum and energy balance equations. The predicted rise of the average electron temperature and the drop of the de conductivity i nduced by the THz radiation, are in reasonably good agreement with rec ent experimental measurements.