Acoustoelectric Effects in Indium Antimonide

Abstract

The acoustoelectric interaction in InSb is developed and investigated on the basis of a hydrodynamical theory. Comparison of numerical results obtained from this theory with the corresponding numerical results from more detailed microscopic theories reveals that the essential features of the microscopic theories are also present in the simpler hydrodynamical theory. In particular, the hydrodynamical theory accounts for the existence of two distinct modes of acoustic domain formation and for the reduction of peak acoustic gain at low values of magnetic field. Valuable insight into the physical basis of the acoustoelectric effect is obtained and it is shown that in the limit of large electron drift velocities and small transverse magnetic field strengths, the Mode I-type acoustoelectric interaction arises from a drift-enhanced quenching of electron diffusion effects. Moreover it is found that the frequency of maximum acoustoelectric gain, as given by the hydrodynamical theory of the present paper, does not occur at the fixed frequency f0 = (ωRωD)1/2/2π, but rather, it is dependent upon the exact values of drift velocity and magnetic field strength. Several computer-generated plots are presented and discussed in order to fully illustrate the results of this investigation.