The phonon properties of CoSb(2) have been investigated by Raman scattering spectroscopy and lattice dynamics calculations. Sixteen out of eighteen Raman active modes predicted by factor-group analysis are experimentally observed and assigned. The calculated and measured phonon energies at the Γ point are in very good agreement. The temperature dependence of the A(g) symmetry modes is well repr...

We predict the existence of coupled plasmon-phonon excitations in graphene by using the self-consistent linear response formalism. The unique electron-phonon interaction in graphene leads to unconventional mixing of plasmon and optical phonon polarizations. We find that longitudinal plasmons couple exclusively to transverse optical phonons, whereas graphene’s transverse plasmons couple only to ...

We comprehensively examine the importance of phonons on the optical properties of GaN. Using Raman and photoluminescence PL spectroscopies, the energies and linewidths of optic phonons, excitons, and discrete phonon sidebands PSBs are studied between 20 and 325 K. The temperature dependence of the A1 LO phonon energy and linewidth are described by a combined twoand three-phonon decay process. T...

Boltzmann Transport Equation is solved numerically to model phonon transport in a subcontinuum domain in order to study heat transfer in thin film semiconductors. The phonon distribution function is modified to get an Energy equation from the Boltzmann Transport Equation. Gray form of the Energy equation is solved in the Relaxation time approximation to get the Phonon Energy Density distributio...

A variational solution of the coupled electron-phonon Boltzmann equations is used to calculate the phonon drag contribution to the thermopower in a one-dimensional system. A simple formula is derived for the temperature dependence of the phonon drag in metallic single-walled carbon nanotubes. Scattering between different electronic bands yields nonzero values for the phonon drag as the Fermi le...

Similar to electron waves, the phonon states in semiconductors can undergo changes induced by external boundaries. However, despite strong scientific and practical importance, conclusive experimental evidence of confined acoustic phonon polarization branches in individual free-standing nanostructures is lacking. Here we report results of Brillouin-Mandelstam light scattering spectroscopy, which...

An ab initio based framework for quantitatively assessing the phonon contribution due to magnon-phonon interactions and lattice expansion is developed. The theoretical results for bcc Fe are in very good agreement with high-quality phonon frequency measurements. For some phonon branches, the magnon-phonon interaction is an order of magnitude larger than the phonon shift due to lattice expansion...

We have developed specially designed semiconductor devices for the measurement of thermal conductance in suspended nanostructures. By means of a novel subtractive comparison, we are able to deduce the phonon thermal conductance of individual nanoscale beams of different geometry and dopant profiles. The separate roles of important phonon scattering mechanisms are analyzed and a quantitative est...

The phonon frequencies of metallic ultrathin films were studied by the resonant acoustic-phonon spectroscopy using femtosecond pump-probe method. We excite and detect the acoustic-phonon resonances in the thin films thinner than 50 nm using the femtosecond light pulses. The pump light causes the phonon vibrations through the thermal expansion at the film surface. For the ultrathin films, the st...

We measure the lifetime of the zone-center 340 GHz longitudinal phonon mode in a GaAs-AlAs superlattice excited and probed with femtosecond laser pulses. By comparing measurements conducted at room temperature and liquid nitrogen temperature we separate the intrinsic (phonon-phonon scattering) and extrinsic contributions to phonon relaxation. The estimated room temperature intrinsic lifetime of...