SOLITARY-WAVE CONDUCTION IN P-TYPE GE UNDER TIME-DEPENDENT VOLTAGE BIAS

We present the results of numerical simulations of a drift-diffusion m odel-including electric-field-dependent generation-recombination proce sses-for closely compensated p-type Ge at low temperature and under dc +ac and dc+noise voltage biases, with an Ohmic boundary condition. We observe frequency locking and quasiperiodicity under dc+ac bias, but d o not find chaotic behavior for a uniform impurity profile. Noise-indu ced intermittent switching near the onset of solitary-wave conduction is compared to experimentally observed intermittency, type-III intermi ttency, and on-off intermittency. For a linearly increasing acceptor c oncentration, we find that the size of the solitary waves diminishes a s they advance across the sample.