Spatiotemporal dynamics of current-density filaments in a periodically driven multilayered semiconductor device

Results of numerical calculations of a set of reaction-diffusion equations for silicon p(+)-n(+)-p-n(-) devices under de and ac bias are presented. Fo r pure de bias, we observe self-sustained oscillations of the device voltag e accompanied with pendulumlike oscillations of a current-density filament. By imposing an ac bias the device voltage shows frequency locking, quasipe riodicity, and chaos depending on the amplitude and the frequency of the ac bias. It is shown that the global oscillations are connected with correspo nding frequency-locked, quasiperiodic, and chaotic filament motions. The nu merical results reproduce the bifurcation sequences observed recently in ex periments on multilayered silicon structures. [S0163-1829(99)00311-2].