Abstract
In the present work, we theoretically studied the acoustic phonon modes in a NWSL composed of cubic materials. Based on the group theory, the acoustic phonon modes were classified. We found there exist four independent phonon modes in the rectangular cross-section GaAs/AlAs NWSLs. Using the XYZ algorithm, we calculated dispersion relations for each mode. The overall structure of the phonon dispersion relations can be understood by the folding of the dispersion curves in the subband structure of a homogeneous plain wire. Phononic band gaps are generated at the center and edges of the mini-BZ. Here, we note that dispersion relations depend on the shape of the cross-section of a NWSL. The results for square and circular cross-section NWSLs will be given elsewhere. Furthermore, it would be interesting to consider a phononic crystal consisting of two-dimensional arrays of NWSLs.
