The coupling of Bloch oscillations to longitudinal optical phonons is investigated in a narrow-well In0.53Ga0.47As/In0.52Al0.48As superlattice. A strong increase of coherent phonon amplitudes is observed when the Bloch oscillations are subsequently tuned into resonance with different optical phonon modes. The rapid dephasing of the Bloch oscillations due to field induced tunneling from the weak...

Phonons, the quantum mechanical representation of lattice vibrations, and their coupling to the electronic degrees of freedom are important for understanding thermal and electric properties of materials. For the first time, phonons have been measured using resonant inelastic x-ray scattering (RIXS) across the Cu K-edge in cupric oxide (CuO). Analyzing these spectra using an ultra-short core-hol...

Ultrafast coherent generation of acoustic phonons is studied in a semiconductor optical microcavity. The confinement of the light pulse amplifies both the generation and the detection of phonons. In addition, the standing wave character of the photon field modifies the generation and detection phonon bandwidth. Coherent generation experiments in an acoustic nanocavity embedded in an optical mic...

Analysis of acoustic phonons modulated due to the surfaces of a free-standing semiconductor plate and their deformation-potential interaction with electrons are presented. The form factor for electron-modulated acoustic phonon interaction is formulated and analyzed in detail. The form factor at zero in-plane phonon wave vector satisfies sum rules regardless of electron wave function. The form f...

We report a direct determination of the specular scattering probability of acoustic phonons at a crystal boundary by observing the escape of incident coherent phonons from the coherent state during reflection. In the sub-THz frequency range where the phonon wavelength is much longer than the lattice constant, the acoustic phonon-interface interaction is found to agree well with the macroscopic ...

The performance of carbon nanotube field-effect transistors is analyzed numerically, using the non-equilibrium Green's function formalism. The effect of electron-phonon scattering on both the DC and switching response of these devices is studied. For the calculation of the switching response, the quasi-static approximation is assumed. The role of the electron-phonon coupling strength and phonon...

The electron-phonon coupling (EPC) strength for each phonon mode in superconducting Pb films is measured by inelastic helium atom scattering (IHAS). This surprising ability of IHAS relies on two facts: (a) In ultrathin metal films, the EPC range exceeds the film thickness, thus enabling IHAS to detect most film phonons, even 1 nm below the surface; (b) IHAS scattering amplitudes from single pho...

Density-functional calculations of the phonon spectrum and electron-phonon coupling in MgB (2) are presented. The E(2g) phonons, which involve in-plane B displacements, couple strongly to the p(x,y) electronic bands. The isotropic electron-phonon coupling constant is calculated to be about 0.8. Allowing for different order parameters in different bands, the superconducting lambda in the clean l...

We present a microscopic model for systems showing resistivity saturation. An essentially exact quantum Monte Carlo calculation demonstrates that the model describes saturation. We give a simple explanation for saturation, using charge conservation and considering the limit where thermally excited phonons have destroyed the periodicity. Crucial model features are phonons coupling to the hopping...

Rotation and reflection symmetries impose that out-of-plane (flexural) phonons of freestanding graphene membranes have a quadratic dispersion at long wavelength and can be excited by charge carriers in pairs only. As a result, we find that flexural phonons dominate the phonon contribution to the resistivity rho below a crossover temperature T(x) where we obtain an anomalous temperature dependen...