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Related papers: Phonon dispersion and lifetimes in MgB2

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We develop a theory of the linear optical spectrum of excitons in quantum dot molecules, including the effect of exciton-phonon coupling beyond the Markov limit. The model reproduces the general trend of the zero-phonon line broadening as a…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Gaetano Parascandolo , Vincenzo Savona

Recent optical studies in c-axis oriented superconducting MgB$_2$ films indicate that the electron-phonon coupling is weak [tu01]. We reinforce this conclusion by examining the raw reflectance data; its frequency dependence is incompatible…

Superconductivity · Physics 2009-11-07 F. Marsiglio

The phonon dispersion of graphene on Ir(111) has been determined by means of angle-resolved inelastic electron scattering and density functional calculations. Kohn anomalies of the highest optical-phonon branches are observed at the…

Materials Science · Physics 2015-06-17 M. Endlich , A. Molina-Sánchez , L. Wirtz , J. Kröger

We report an investigation of the bulk and surface acoustic phonons in gallium oxide ultra-wide bandgap single crystals along various crystallographic directions using Brillouin-Mandelstam spectroscopy. Pronounced anisotropy in the acoustic…

We investigate the effects of crystal lattice vibrations on the dispersion of plasmons. The loss function of the homogeneous electron gas (HEG) in two and three dimensions is evaluated numerically in presence of electronic coupling to an…

Materials Science · Physics 2018-05-17 Fabio Caruso , Dino Novko , Claudia Draxl

A time-resolved observation of coherent interlayer longitudinal acoustic phonons in 2$H$-MoSe$_2$ is reported. A femtosecond pump-probe technique is used to investigate the evolution of the energy loss of these vibrational modes in a wide…

Mesoscale and Nanoscale Physics · Physics 2019-07-11 P. Soubelet , A. A. Reynoso , A. Fainstein , K. Nogajewski , M. Potemski , C. Faugeras , A. E. Bruchhausen

The distribution function of electrons and phonons interacting with electrons in semiconductors and semimetals in high electric and quantizing magnetic fields as a result of the solution of the coupled system of equations for the density…

Condensed Matter · Physics 2007-05-23 T. M. Gassym

We report results of inelastic neutron scattering measurements of phonon dispersions on a detwinned sample of YBaCu3O7 and compare them with model calculations. Plane oxygen bond stretching phonon branches disperse steeply downwards from…

Superconductivity · Physics 2007-05-23 D. Reznik , L. Pintschovius , W. Reichardt , Y. Endoh , H. Hiraka , J. M. Tranquada , S. Tajima , H. Uchiyama , T. Masui

$Ab-initio$ probabilities of phonon-assisted intervalley scattering of electrons in the conduction bands of ternary chalcopyrite compounds $ZnSiP_2$ and $ZnGeP_2$ between the central $\Gamma$ minima and the lowest lateral minima (valleys)…

Materials Science · Physics 2019-10-08 V. G. Tyuterev

The Raman peak position and linewidth provide insight into phonon anharmonicity and electron-phonon interactions (EPI) in materials. For monolayer graphene, prior first-principles calculations have yielded decreasing linewidth with…

Materials Science · Physics 2022-01-27 Zherui Han , Xiaolong Yang , Sean E. Sullivan , Tianli Feng , Li Shi , Wu Li , Xiulin Ruan

The possibility of magnetic-order induced phonon anisotropy in single crystals of MnO and NiO is investigated using inelastic neutron scattering. Below Tn both compounds exhibit a splitting in their transverse optical phonon spectra of…

Strongly Correlated Electrons · Physics 2009-11-10 E. M. L. Chung , D. McK. Paul , G. Balakrishnan , M. R. Lees , A. Ivanov , M. Yethiraj

We used polarization-resolved Raman scattering to study magneto-elastic coupling in Ba(Fe$_{1-x}$Au$_{x}$)$_2$As$_2$ crystals as a function of light Au-doping, materials for which temperatures of the structural transition ($T_S$) and of the…

Superconductivity · Physics 2020-07-15 S. -F. Wu , W. -L. Zhang , L. Li , H. -B. Cao , H. -H. Kung , A. S. Sefat , H. Ding , P. Richard , G. Blumberg

We employ inelastic helium atom-surface scattering to measure the low energy phonon dispersion along high-symmetry directions on the surface of the topological insulator Bi$_2$Te$_3$. Results indicate that one particular low-frequency…

Materials Science · Physics 2013-07-03 Colin Howard , M. El-Batanouny , R. Sankar , F. C. Chou

We investigate the dispersion and temperature dependence of a number of phonons in the recently discovered superconductor CaC6 utilizing inelastic x-ray scattering. Four [00L] and two ab-plane phonon modes are observed, and measured at…

The effect of pressure on the zone-center optical phonon modes and the elastic properties of hafnium has been studied by both experimental (Raman scattering) and theoretical (DFT) approaches. It was found an anomaly dependence of the phonon…

Materials Science · Physics 2018-06-06 D. Novoselov , V. I. Anisimov , Yu. S. Ponosov

The phonon propagation dynamics in a phononic crystal waveguide, realized via a suspended one-dimensional membrane array with periodic air holes, is investigated as function of its geometry. The bandstructure of the phononic crystal can be…

Mesoscale and Nanoscale Physics · Physics 2019-02-28 Daiki Hatanaka , Amaury Dodel , Imran Mahboob , Koji Onomitsu , Hiroshi Yamaguchi

Taking into account the constraints imposed by the lattice symmetry, we calculate the phonon dispersion for graphene with interactions between the first, second, and third nearest neighbors in the framework of the Born--von Karman model.…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 L. A. Falkovsky

The electron-phonon interaction plays a crucial role in many fields of physics and chemistry. Nevertheless, its actual calculation by means of modern many-body perturbation theory is weakened by the use of model Hamiltonians that are based…

Materials Science · Physics 2015-05-15 Andrea Marini , Samuel Poncé , Xavier Gonze

We calculate the collective charge density excitation dispersion and spectral weight in bilayer semiconductor structures {\it including effects of interlayer tunneling}. The out-of-phase plasmon mode (the ``acoustic'' plasmon) develops a…

Strongly Correlated Electrons · Physics 2009-10-31 S. Das Sarma , E. H. Hwang

We investigate the long-wavelength dispersion of longitudinal and transverse optical phonon modes in polar two-dimensional materials, multilayers, and their heterostructures. Using analytical models and density-functional perturbation…

Materials Science · Physics 2017-08-02 Thibault Sohier , Marco Gibertini , Matteo Calandra , Francesco Mauri , Nicola Marzari