Space-charge buildup and bistability in resonant-tunneling double-barrier structures

Using the sequential theory of resonant tunneling, the dc current-voltage characteristic of a double-barrier structure is calculated, taking into account the effect of space charge in the quantum well. A region of current bistability is found over a voltage range which is determined by the maximum space charge and the capacitance of the structure. These parameters are directly related to the periodicity of magnetoquantum oscillations in the current.