STATIC AND DYNAMIC HYSTERESIS IN DEEP-IMPURITY DOPED N-GAAS UNDER DC BIAS VOLTAGE

Non-linear carrier transport properties of deep-impurity doped n-GaAs at room temperatures are studied with the assumption of spatial homoge neity. The dynamical behavior of the system can be classified into fou r distinct classes, depending on the magnitude of the load resistance R, which is connected in series to the system, along with a d.c. bias voltage V. Global and local bifurcation schemes around the fixed point s are studied in detail. The bifurcation features include creation of a saddle-to-saddle loop via sub-critical Hopf bifurcation, creation an d destruction of a pair of stable and unstable limit cycles via conden sation of paths, and oscillatory instability occurring in the positive conductivity region, etc. When Vis slowly increased from low values a nd then decreased from high values, the system exhibits static switchi ng, dynamic hysteresis, or no hysteresis, depending on the magnitude o f R. We find a case that the system exhibits hysteresis even when the total current is a single-valued function of V.