Quantization of acoustic-phonon shear modes in a nanowaveguide

Acoustic energy trapping in a thin non-piezoelectric plate is studied. The confinement of resonant acoustic fields is described for the case where energy trapping is caused by thickening the center region of the plate. The elastic continuum mechanics model is used to determine the quantized acoustic-phonon modes in an isotropic nanowaveguide. The acoustic-phonon amplitudes and relative frequency dispersion relations are obtained analytically and presented for both the odd symmetry shear modes and even symmetry shear modes. The acoustic-phonon modes in the non-piezoelectric nanowaveguide are quantized. Furthermore, the limit of the quality factor and frequency (fQ) product achievable by a resonator is theoretically discussed and calculated in silicon resonators for three different orientations. Published by AIP Publishing.