Phonon calculations based on first principle electronic structure theory, such as the Kohn–Sham density functional theory, have wide applications in physics, chemistry, and material science. The computational cost of first principle phonon calculations typically scales steeply as O(N4 e ), where Ne is the number of electrons in the system. In this work, we develop a new method for reducing the ...

Phonon exchange is the usual cause of decoherence in atom-surface scattering. By including quantum effects in the treatment of Debye-Waller scattering, we show that phonon exchange becomes ineffective when the relevant phonon frequencies are high. The result explains the surprising observation of strong elastic scattering of Ne from a Cu(100) surface nanotextured with a c(2 × 2) Li adsorbate st...

Introduction Critical point analysis of phonon combination bands in the far-infrared spectra have been widely used to establish precise values for alkalihalide phonon frequencies at major symmetry points in the Brillouin zone /1 to 4/. The high resolution available in far-infrared measurements enables more accurate determination of phonon frequencies than it is possible using neutron scattering...

The phonon spectra emitted by superconducting tunnel junctions were directly analyzed with high resolution using tunable acceptor states of B in Si as a spectrometer. A consistent and detailed experimental picture of the different parts of the spectra under various injection conditions was obtained for the first time. Tunnel injection of electrons into superconductors leads to energetic quasipa...

Recent progress in phonon-mediated detectors with eV-scale nuclear recoil energy sensitivity requires an understanding of the effect crystalline defects on spectrum expected from dark matter or neutrino coherent scattering. We have performed molecular dynamics simulations to determine amount stored lattice as a function direction and energy. This can not be observed phonon measurement, thus aff...

A theory is presented for the dispersion relations of the nonlinear phonon-polaritons arising when phonons are coupled to the electromagnetic waves in multilayered structures of nonlinear materials. The calculations are applied to a multilayered structure consisting of a thin film surrounded by semi-infinite bounding media where each layer may have a frequency dependent dielectric function and ...