HYBRID ELECTRIC-FIELD DOMAINS LEADING TO SPATIOTEMPORAL CHAOS IN N-GAAS

It has been shown that a Gunn diode may exhibit a transition from an o scillating (traveling domains) to a nonoscillating (stationary domains ) state when the electron density in the metal-semiconductor contact a t the cathode can be controlled experimentally [Shiau and Cheng, Solid State Commun. 99, 305 (1996)]. In this paper it is found that spatiot emporal chaos may occur in the Gunn diode when a small ac bias is adde d to drive the stationary domains. The route to spatiotemporal chaos i s found to be period doubling. The bifurcation feature and the spatiot emporal behavior of the electric field are studied in detail.