The polar optical vibrations are essential for the transport properties in semiconductor nanostructures because they are the source of a strong electron-phonon interaction. The commonly used macroscopic models (see for [1] and the bibliography therein) treat the optical phonon displacements as a spatially smooth functions. Our calculation in the realistic three-dimensional lattice-dynamical mod...

This paper is devoted to the derivation of a macroscopic diffusion equation (Fourier’s law) describing the transport of energy in an anharmonic chain. More precisely, we study here the so-called FPU-β chain, which is a very simple model for a one-dimensional crystal in which atoms are coupled to their nearest neighbors by a harmonic potential, weakly perturbed by a quartic potential. The starti...

We report tip-enhanced and conventional Raman spectroscopy studies of Ge-Si0.5Ge0.5 core-shell nanowires in which we observe two distinct Ge-Ge vibrational mode Raman peaks associated with vibrations in the Ge nanowire core and at the Ge-Si0.5Ge0.5 interface at which a quantum-confined hole gas is formed. Tip enhanced Raman measurements show dramatically increased sensitivity to the modes at th...

Scientists and engineers can exploit nanostructures to manipulate thermal transport in solids. This is possible because the dominant heat carriers in nonmetals – crystal vibrations (or phonons) – have characteristic lengths in the nanometer range. We review research where this approach is used and propose future research directions. For instance, concepts such as phonon filtering, correlated sc...

This paper uses an orthotropic shell model to investigate in detail the long axial wavelength circumferential vibration of microtubules (MTs). The deformation patterns in the vibrations were explored and their phonon dispersion relations were presented for MTs with increasing radius. It was shown that with the growth of the axial wavelength, the associated frequency of MTs would finally approac...

We report on spin-flip Raman scattering and on Raman scattering by acoustic phonons in CdS nanocrystals embedded in a glass matrix. We discuss both the spin-flip and the acoustic-phonon Raman spectra on the basis of the interaction of size-quantized electronic excitations with nonconfined acoustic vibrations. The polarization of spin-flip Raman scattering in the Faraday and Voigt configurations...

The numerical calculations of the standard Eliashberg-Nambu strong coupling theory and a formula of isotope effect derived in this paper provide direct evidences that an-harmonic vibrations of lattice enhance isotope effect with anomalous coefficient α > 1/2. The results in this paper explain very well the wide distributed α values for the samples with different ratios of substitutions of 12C b...

We analyze experimentally and theoretically mechanical oscillation within an optical cavity stimulated by the pressure of circulating optical radiation. The resulting radio frequency cavity vibrations (phonon mode) cause modulation of the incident, continuous-wave (cw) input pump beam. Furthermore, with increasing cw pump power, an evolution from sinusoidal modulation to random oscillations is ...

Abstract In an electronic system of solids excited by a femtosecond laser pulse, new quantum states called photon-dressed are created via the coupling original electron wavefunctions and periodic electric fields light. The study is central issue in nonlinear optical science, as coherent response associated with state can cause ultrafast optical-switching phenomena. general, however, phase-sensi...