Elastic layered waves in (001) III-V nitride systems

Abstract

We have studied the acoustic waves in ͑001͒ single and multielastic wells formed by AlN, GaN, and InN in the zinc-blende structure. We have used the surface Green function matching method to obtain the dispersion relations and the local density of states. The anisotropy of the materials is included and the different propagation directions ranging from the ͓1,0,0͔ to the ͓1,1,0͔ have been considered. In these symmetry directions the sagittal waves are associated with a different velocity threshold than the transverse ones, thus showing a different behavior to that found in the isotropic case. For the ͓1,1,0͔ direction the sagittal modes are confined to a different range of velocities than the transverse modes. It has been found that the anisotropy introduces a more complex picture with a different mixing of the displacement components and the existence of different characteristics for different ranges of propagation direction.