Multistability of the current‐voltage characteristics in doped GaAs‐AlAs superlattices

Electric‐field domain formation in doped semiconductor superlattices leads to sharp discontinuities in the current‐voltage (I‐V) characteristic. The successive expansion of the high‐field region with increasing bias voltage through the periodic heterostructure manifests itself in a regular sequence of stable current branches. The current shows a complex hysteretic behavior. We observe two, three, and more stable current levels for fixed bias voltages. Calculations of the I‐V characteristic based on a microscopic model support the experimentally observed multistability.