THz acoustic spectroscopy based on GaN nanostructures

Due to the high attenuation in vitreous silica, acoustic attenuations in the THz regime are typically measured by incoherent techniques such as Raman, neutron, and X-ray scattering. Here, we utilized multiple-quantum-well structures to demonstrate acoustic spectroscopy of vitreous silica up to THz regime. The acoustic properties of silica thin films prepared by chemical deposition methods were characterized in the sub-THz regime. This technique may be useful in resolving debated issues relating to Boson peak around 1 THz.