Intermittency in low frequency current oscillations in semi-insulating GaAs

Spontaneous low frequency current oscillations were observed in semi-insulating crystalline GaAs. If the value of the applied voltage U was increased, a crisis induced intermittency was observed. The time intervals between successive transitions were measured. For values of the control parameter U larger than a critical value two interacting chaotic subattractors were observed. The average time intervals are scaling with the control parameter with a critical exponent very close to −1/2.