Microwave Emission from Acoustoelectrically Oscillating n-InSb

Abstract

The microwave radiation of 4 GHz was emitted at 77°K from a bar of n-InSb with axis parallel to [110] direction, when it was subjected to an electric field of about 30 V/cm, with or without the magnetic field. The detected microwave emission consisted of a number of spikes and amplitude-modulated with the acoustoelectric oscillation. The length of the sample enough to emit the microwave radiation was about 1 cm in accordance with the minimum length for exciting the acoustoelectric oscillation. The application of the transverse magnetic field enhanced the microwave emission and as for its electric and magnetic field dependence there were close correlations between the microwave emission and acoustoelectric effect. Finally the microwave emission of n-InSb at the low field is concluded to be due to the build-up of phonons caused by the piezoelectrical coupling.