title: Thermal Boundary Resistance between GaN and Cubic Ice and THz Acoustic Attenuation Spectrum of Cubic Ice from Complex Acoustic Impedance Measurements.
abstract: A phonon nanoscopy method, based on the picosecond ultrasonics technique, capable of studying the complex acoustic reflection coefficient at frequency up to 1 THz is proposed and demonstrated. By measuring the reflection coefficient at the same surface location at the interface between GaN and air, and between GaN and the material to characterize, we get access to the THz amplitude and phase spectra of the acoustic phonon reflection. The retrieval of both these pieces of information then allows the calculation of the attenuation in a wide range of frequency and gives new insight into the Kapitza anomaly. This method is then applied to cubic ice, and the measurements of the elastic properties, the phonon anharmonic decay spectrum up to 1 THz, as well as the measurements of the thermal phonon lifetime at 150 K are all achieved.
authors: Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan.
authors: Pierre-Adrien
authors: PA
authors: Mante
authors: Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan.
authors: Chien-Cheng
authors: CC
authors: Chen
authors: Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan.
authors: Yu-Chieh
authors: YC
authors: Wen
authors: Institute of Electro-Optical Science and Engineering and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan.
authors: Jinn-Kong
authors: JK
authors: Sheu
authors: Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan and Molecular Imaging Center, National Taiwan University, Taipei 10617, Taiwan and Institute of Physics, Academia Sinica, Taipei 115, Taiwan.
authors: Chi-Kuang
authors: CK
authors: Sun