Transverse coupling in bistable resonant-tunneling structures

We demonstrate that transverse redistribution of the built-up electron concentration n in the quantum well of a bistable double barrier resonant-tunneling diode can be represented as effective diffusion, and derive an explicit expression for the concentration-dependent diffusion coefficient $D\left(n\right)\mathrm{}$ which covers the full range from nondegenerate to degenerate statistics of the two-dimensional electron gas in the well. Further, we discuss the impact of such transverse coupling on lateral current-density patterns.