DYNAMICAL LOCALIZATION, STIMULATED ABSORPTION AND EMISSION IN A DOUBLE-QUANTUM-WELL, INDUCED BY A THZ FIELD

We analyze the I-V characteristics of a double quantum well driven by THz radiation. We perform a self-consistent calculation in order to ev aluate the sequential current, where the electron-electron interaction is treated in a mean field approximation and temperature and scatteri ng effects are included. In the presence of the AC field some interest ing new physical features appear: dynamical localization for some valu es of the frequency and intensity of the field and negative conductanc e in the low-bias regime. These phenomena, already observed in superla ttices are explained by means of our model. We compare our results wit h recent experimental information. (C) 1997 Academic Press Limited.