Tuning of semiconductor oscillators by chaos control

It is demonstrated theoretically that a stable and tunable semiconductor oscillator can be designed by using a novel method of chaos control. By application of a small time-continuous delayed feedback voltage control signal, different unstable periodic orbits embedded in the chaotic attractor of a semiconductor can be stabilized. Thus different modes of self-generated periodic voltage oscillations can be selected, for example by choosing an appropriate delay time. This is illustrated for two different oscillation mechanisms involving hot-carrier transport: (i) self-generated oscillations under crossed electric and magnetic fields in the regime of low-temperature impurity breakdown (dynamic Hall effect), and (ii) driven real-space transfer oscillations in modulation-doped heterostructures.