DYNAMIC INSTABILITIES IN RESONANT-TUNNELING INDUCED BY A MAGNETIC-FIELD

We show that the addition of a magnetic field parallel to the current induces self-sustained intrinsic current oscillations in an asymmetric double barrier structure. The oscillations are attributed to the nonl inear dynamic coupling of the current to the charge trapped in the wel l, and the effect of the external field over the local density of stat es across the system. Our results show that the system bifurcates as t he field is increased, and may transit to chaos at large enough fields .