SPIKES IN THE CURRENT SELF-OSCILLATIONS OF DOPED GAAS ALAS SUPERLATTICES/

In doped, weakly coupled superlattices, current self-oscillations occu r due to a recycling motion of a charge monopole, which forms the boun dary between two electric field domains. Tn addition to these fundamen tal oscillations, the current also contains a high-frequency modulatio n in form of spikes, which are caused bg the tunneling process of the charge monopole over a single superlattice period. The number of spike s within one fundamental oscillation can therefore serve as a measure for the number of superlattice periods, which are involved in the recy cling motion. Spiking may reflect non-stationary tunneling effects for sufficiently large applied electric fields.