TUNING OF SEMICONDUCTOR OSCILLATORS BY CHAOS CONTROL

It is demonstrated theoretically that a stable and tunable semiconduct or oscillator can be designed by using a novel method of chaos control . By application of a small time-continuous delayed feedback voltage c ontrol signal, different unstable periodic orbits embedded in the chao tic attractor of a semiconductor can be stabilized. Thus different mod es of self-generated periodic voltage oscillations can be selected, fo r example by choosing an appropriate delay time. This is illustrated f or two different oscillation mechanisms involving hot-carrier transpor t: (i) self-generated oscillations under crossed electric and magnetic fields in the regime of low-temperature impurity breakdown (dynamic H all effect), and (ii) driven real-space transfer oscillations in modul ation-doped heterostructures.