Observation of low frequency oscillations in GaAs samples grown by molecular beam epitaxy at low temperatures

We have observed Low Frequency Oscillations (LFO) in a GaAs sample grown by molecular beam epitaxy (MBE) at 300 degrees C as a function of applied electric field, temperature and illumination intensity. Time series of the oscillations for different values of the applied electric field at room temperature were obtained. We have also obtained the jxE characteristics as a function of temperature and light intensity. We were able to control the LFO using three experimental parameters, the electrical field, which controls the oscillation frequency, and the temperature and illumination intensity, which control the carrier density and field-enhanced trapping. We were able to identify the LFO dependence on the carrier density and on the field-enhanced trapping.