Self-organization in semiconductor physics

Non-equilibrium dissipative systems from semiconductor physics have prevailed as a paradigmatic testing field for complex non-linear dynamics during the last decade. Especially, low-temperature impact ionization breakdown in extrinsic germanium crystals displays a variety of interesting nonlinear phenomena, such as spontaneous oscillations and filamentary patterns of the current flow. We report on recent experimental results concerning the interplay between spatial and temporal degrees of freedom during the onset of semiconductor breakdown. Quantitative evaluation of characteristic scaling properties supports the applicability of the model of self-organized criticality.