Effect of charge fluctuations on the phonon dispersion and electron-phonon interaction inLa2CuO4

1993 ◽  
Vol 47 (9) ◽  
pp. 5390-5404 ◽  
Author(s):  
C. Falter ◽  
M. Klenner ◽  
W. Ludwig
Keyword(s):  
Phonon Dispersion ◽  
Phonon Interaction ◽  
Charge Fluctuations ◽  
Electron Phonon Interaction

Electron–Phonon Interaction Model and Prediction of Thermal Energy Transport in SOI Transistor

2007 ◽  
Vol 7 (11) ◽  
pp. 4094-4100 ◽  
Author(s):  
Jae Sik Jin ◽  
Joon Sik Lee
Keyword(s):  
Energy Density ◽  
Group Velocity ◽  
Phonon Scattering ◽  
Phonon Dispersion ◽  
Dispersion Model ◽  
Hot Spot ◽  
Interaction Model ◽  
Phonon Interaction ◽  
Electron Phonon Interaction ◽  
Electron Phonon Scattering

An electron–phonon interaction model is proposed and applied to thermal transport in semiconductors at micro/nanoscales. The high electron energy induced by the electric field in a transistor is transferred to the phonon system through electron–phonon interaction in the high field region of the transistor. Due to this fact, a hot spot occurs, which is much smaller than the phonon mean free path in the Si-layer. The full phonon dispersion model based on the Boltzmann transport equation (BTE) with the relaxation time approximation is applied for the interactions among different phonon branches and different phonon frequencies. The Joule heating by the electron–phonon scattering is modeled through the intervalley and intravalley processes for silicon by introducing average electron energy. The simulation results are compared with those obtained by the full phonon dispersion model which treats the electron–phonon scattering as a volumetric heat source. The comparison shows that the peak temperature in the hot spot region is considerably higher and more localized than the previous results. The thermal characteristics of each phonon mode are useful to explain the above phenomena. The optical mode phonons of negligible group velocity obtain the highest energy density from electrons, and resides in the hot spot region without any contribution to heat transport, which results in a higher temperature in that region. Since the acoustic phonons with low group velocity show the higher energy density after electron–phonon scattering, they induce more localized heating near the hot spot region. The ballistic features are strongly observed when phonon–phonon scattering rates are lower than 4 × 1010 s−1.

Electron–Phonon Interaction Model and Prediction of Thermal Energy Transport in SOI Transistor

2007 ◽  
Vol 7 (11) ◽  
pp. 4094-4100
Author(s):  
Jae Sik Jin ◽  
Joon Sik Lee
Keyword(s):  
Energy Density ◽  
Group Velocity ◽  
Phonon Scattering ◽  
Phonon Dispersion ◽  
Dispersion Model ◽  
Hot Spot ◽  
Interaction Model ◽  
Phonon Interaction ◽  
Electron Phonon Interaction ◽  
Electron Phonon Scattering

An electron–phonon interaction model is proposed and applied to thermal transport in semiconductors at micro/nanoscales. The high electron energy induced by the electric field in a transistor is transferred to the phonon system through electron–phonon interaction in the high field region of the transistor. Due to this fact, a hot spot occurs, which is much smaller than the phonon mean free path in the Si-layer. The full phonon dispersion model based on the Boltzmann transport equation (BTE) with the relaxation time approximation is applied for the interactions among different phonon branches and different phonon frequencies. The Joule heating by the electron–phonon scattering is modeled through the intervalley and intravalley processes for silicon by introducing average electron energy. The simulation results are compared with those obtained by the full phonon dispersion model which treats the electron–phonon scattering as a volumetric heat source. The comparison shows that the peak temperature in the hot spot region is considerably higher and more localized than the previous results. The thermal characteristics of each phonon mode are useful to explain the above phenomena. The optical mode phonons of negligible group velocity obtain the highest energy density from electrons, and resides in the hot spot region without any contribution to heat transport, which results in a higher temperature in that region. Since the acoustic phonons with low group velocity show the higher energy density after electron–phonon scattering, they induce more localized heating near the hot spot region. The ballistic features are strongly observed when phonon–phonon scattering rates are lower than 4 × 1010 s−1.

Lattice dynamics of sodium

1963 ◽  
Vol 276 (1366) ◽  
pp. 308-323 ◽  
Keyword(s):  
Effective Potential ◽  
Lattice Dynamics ◽  
Periodic Potential ◽  
Phonon Dispersion ◽  
Plane Waves ◽  
Point Of View ◽  
Phonon Interaction ◽  
Conduction Electrons ◽  
Electron Phonon Interaction ◽  
The Matrix

The method of orthogonalized plane waves has been shown to lead to the concept of an effective potential for the interaction of the conduction electrons with the periodic potential of the lattice. It has been further demonstrated by Sham that the effective potential may be regarded as moving rigidly with the ions in the course of the lattice vibrations. The experimental results of Woods, Brockhouse, March, Stew art & Bowers (1962) on the phonon dispersion relation in sodium have been analyzed from this point of view. It is found that the results are consistent with the concept of an effective potential, which is deduced empirically and found to have qualitatively the form expected. Certain features of the matrix element for electron-phonon interaction can also be deduced from the experimental data. The force constants derived by Woods et al. can be interpreted quantitatively in terms of the effective potential and electron screening effects. Other features of the results are discussed.

scholarly journals Influence of the electron-phonon iinteraction on phonon heat conduction in a molecular nanowire

2006 ◽  
Vol 38 (2) ◽  
pp. 125-129
Author(s):  
Slobodanka Galovic ◽  
D. Cevizovic ◽  
S. Zekovic ◽  
Z. Ivic
Keyword(s):  
Heat Conduction ◽  
Dispersion Relation ◽  
Acoustic Phonon ◽  
Phonon Dispersion ◽  
Phonon Interaction ◽  
Electron Phonon Interaction ◽  
Phonon Dispersion Relation

A model for phonon heat conduction in a molecular nanowire is developed. The calculation takes into account modification of the acoustic phonon dispersion relation due to the electron-phonon interaction. The results obtained are compared with models based upon a simpler, Callaway formula.

Surface lattice dynamics and electron–phonon interaction in cesium ultra-thin films

2017 ◽  
Vol 19 (25) ◽  
pp. 16358-16364 ◽  
Author(s):  
D. Campi ◽  
M. Bernasconi ◽  
G. Benedek ◽  
A. P. Graham ◽  
J. P. Toennies
Keyword(s):  
Ultrathin Films ◽  
Density Functional ◽  
Phonon Dispersion ◽  
Phonon Interaction ◽  
Phonon Dispersion Curves ◽  
Helium Atom Scattering ◽  
Electron Phonon Interaction ◽  
Atom Scattering ◽  
Density Functional Perturbation Theory ◽  
Mass Enhancement

The phonon dispersion curves of ultrathin films of Cs(110) on Pt(111) measured with inelastic helium atom scattering (HAS) are reported and compared with density-functional perturbation theory calculations. The mass-enhancement factor is derived from the temperature dependence of the HAS Debye–Waller exponent.

Phonon Properties of Americium Sulphide

2016 ◽  
Vol 28 ◽  
pp. 125-128
Author(s):  
Balwant Singh Arya ◽  
Mahendra Aynyas ◽  
Sankar P. Sanyal
Keyword(s):  
Present Model ◽  
Phonon Dispersion ◽  
Dispersion Curves ◽  
Phonon Interaction ◽  
Phonon Dispersion Curves ◽  
Electron Phonon Interaction ◽  
Breathing Motion ◽  
Shell Models ◽  
Phonon Properties

We have reported the phonon properties of AmS by using breathing shell models (BSM) which includes breathing motion of electrons of the Am atoms due to f-d hybridization. The phonon dispersion curves, density of states and specific heat calculated from present model. The calculated phonon dispersion curves of AmS are presented follow the same trend as observed in uranium sulphide. We have discussed the significance of this approach in predicting the phonon dispersion curves of this compound and examine the role of electron-phonon interaction.

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