MAGNETIC-FIELD EFFECTS ON THE HYSTERESIS IN SEMICONDUCTORS WITH AN S-SHAPED NEGATIVE DIFFERENTIAL CONDUCTIVITY

A theory is given to explain the magnetic-field effects on the hystere sis properties in semiconductors with an S-shaped negative differentia l conductivity observed recently by Aoki, Kondo, and Watanabe [Solid S tate Commun. 77, 91 (1991)]. For the longitudinal magnetic-field case, the holding voltage V-h moves to higher voltages, and the difference between the threshold voltage V-th and holding voltage V-h diminishes as B increases. A critical field B-c is reached when V-th=V-h, and cro ssover current instabilities and self-generated chaos are observed for B>B-c. For the transverse magnetic-field case, the difference V-th-V- h becomes larger as B increases.