Chaotic Current Oscillations in the Gunn-Effect Device Under the dc and the rf Bias Voltages

Abstract

A one-dimensional model system of the Gunn-effect device is considered. It consists of an n + - n - n + GaAs sandwich structure where the high- n + contact layers on both ends are linearly graded to the uniformly distributed low- n bulk region and a half-wave sinusoidal doping notch is incorporated near the cathode. Using the finite differece method, spatio-temporal evolution of the system subject to the dc and the rf-alternating fields is computed with the amplitudes and the frequency being taken as the control parameters. Current oscillations associated with the cyclic traveling high-electric-field domain are shown to materialize over a range of the control parameters. In particular, the current oscillations become chaotic at specially chosen values of these bias parameters.