Various routes to chaos in n-GaAs compensated with Ni impurities

We consider the dynamical behavior of non-linear carrier transport for n-GaAs compensated with Ni deep impurities at room temperature. When both dc and ac external biases are applied simultaneously, the system exhibits a richness of bifurcation features as the amplitude of the ac bias varies continuously while the dc bias is kept fixed at a suitable value. These features include period-doubling and period-halving cascades, type-I and type-III intermittencies, frequency-locked behavior, and the coexistence of different attractors.