Coherent excitation and control of lattice motion by electromagnetic radiation in optical frequency range has been reported through variety of indirect interaction mechanisms with phonon modes. However, coherent phonon excitation by direct interaction of electromagnetic radiation and nuclei has not been demonstrated experimentally in terahertz (THz) frequency range mainly due to the lack of THz...

Optical phonon confinement and efficient UV emission of ZnO nanowires were investigated in use of resonant Raman scattering (RRS) and photoluminescence (PL). The high-quality ZnO nanowires with diameters of 80-100 nm and lengths of several micrometers were epitaxially grown through a simple low-pressure vapor-phase deposition method at temperature 550 degrees C on the precoated GaN(0001) buffer...

Infrared transmission measurements reveal the hybridization of graphene plasmons and the phonons in a monolayer hexagonal boron nitride (h-BN) sheet. Frequency-wavevector dispersion relations of the electromagnetically coupled graphene plasmon/h-BN phonon modes are derived from measurement of nanoresonators with widths varying from 30 to 300 nm. It is shown that the graphene plasmon mode is spl...

The infrared reflectance of the transition-metal chalcogenide 1T-TaS2 has been measured at temperatures from 30 K to 360 K over 30–45 000 cm ~4 meV–5.5 eV!. The optical conductivity was obtained by Kramers-Kronig analysis. At 360 K only modest traces of the phonon lines are noticeable. The phonon modes are followed by a pseudo-gap-like increase of the optical conductivity, with direct optical t...

We have studied the electron mobility in the AlN/GaN/AlN heterostructures with the nanometer scale thickness by taking into account multiple quantized electron subbands and the confined optical phonon dispersion. It was shown that the inter-subband electronic transitions play an important role in limiting the electron mobility in the heterostructures when the energy separation between one of th...

Single walled carbon nanotubes with Pd Ohmic contacts and lengths ranging from several microns down to 10 nm are investigated by electron transport experiments and theory. The mean-free path (MFP) for acoustic phonon scattering is estimated to be l(ap) approximately 300 nm, and that for optical phonon scattering is l(op) approximately 15 nm. Transport through very short (approximately 10 nm) na...

The Reststrahl spectral region of Silicon Carbide has recently attracted much attention owing to its potential for mid-infrared nanophotonic applications based on surface phonon polaritons (SPhPs). Studies of optical phonon resonances responsible for surface polariton formation, however, have so far been limited to linear optics. In this Letter, we report the first nonlinear optical investigati...

Monoclinic HfO2 nanoparticles (9 45 nm) are synthesized using a sol-gel method and optically characterized using transmissionand angle-dependent reflection spectroscopy in the midto far-infrared. A detailed HfO2 identification of the infrared-active phonon modes is presented; consistent with previously reported thin film values, and in excellent agreement with density functional perturbation th...

Infrared reflection spectra of bulk semiconductors and superlattices can be predicted mathematically with optical phonon frequencies as some of the input variables. This method will be used to determine the polar longitudinal and transverse optical phonons modes and their corresponding energies that are present in AlN/GaN superlattices. Theoretical results will be compared to reflection experim...

The temperature dependence of the band gap of semiconducting single-wall carbon nanotubes (SWNTs) is calculated by direct evaluation of electron-phonon couplings within a "frozen-phonon" scheme. An interesting diameter and chirality dependence of E(g)(T) is obtained, including nonmonotonic behavior for certain tubes and distinct "family" behavior. These results are traced to a strong and comple...