SUPPRESSION OF THE COHERENT CHARGE OSCILLATIONS IN COUPLED QUANTUM-WELLS BY AN INPLANE MAGNETIC-FIELD

A magnetic field H applied parallel to the layers of a double-quantum- well system (DQWs) modifies the energy spectrum of the electrons, givi ng rise to a suppression of tunnel coupling of the electron scales. Da mping of the coherent charge oscillations in DQWs due to this effect i s considered theoretically. A significant damping appears at H>H-0, wh ere H-0 similar to 1 T for typical parameters of the DQWs and excitati on pulse. Two regimes of the damping are described: a small magnetic f ield (H similar to H-0) modifies both the amplitude and temporal evolu tion of the electron density, while a high field (H much greater than H-0) suppresses the amplitude, but has no effect on the temporal evolu tion. In this last case, the oscillations show nonharmonic Bessel-like behavior and their period is determined only by the tunnel coupling e nergy. (C) 1996 American Institute of Physics.