Time resolved response of 2DEG to the coherent component accompanying heat pulses in GaAs

Abstract

The two components, coherent and non-coherent, of acoustical excitations accompanying heat pulse generation have been investigated in GaAs. It was shown that delta-doped layers imbedded into the GaAs crystal exhibit the peculiar property to be sensitive to a high frequency phonon flux and to concomitant coherent acoustic waves simultaneously. The time resolved measurements allow separating longitudinal LA and transverse TA acoustic excitations and investigating the intensity behavior as a dependence on the crystallographic direction of the propagation. The semi quantitative analysis of the layers response to coherent waves of different polarizations has been proposed.