scholarly journals Coherent optical phonon oscillation and possible electronic softening in WTe2 crystals

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Bin He ◽  
Chunfeng Zhang ◽  
Weida Zhu ◽  
Yufeng Li ◽  
Shenghua Liu ◽  
...  
Keyword(s):  
Optical Phonon ◽  
Phonon Oscillation

Polar Optical Phonon Instability and Intervalley Transfer in Gallium Nitride

1998 ◽  
Vol 512 ◽  
Author(s):  
B. E. Foutz ◽  
S. K. O'leary ◽  
M. S. Shur ◽  
L. F. Eastman ◽  
B. L. Gelmont ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Analytical Model ◽  
Optical Phonon ◽  
Room Temperature ◽  
Phonon Scattering ◽  
Polar Optical Phonon ◽  
Scattering Mechanism ◽  
Loss Mechanism ◽  
One Dimensional ◽  
Optical Phonon Scattering

ABSTRACTWe develop a simple, one-dimensional, analytical model, which describes electron transport in gallium nitride. We focus on the polar optical phonon scattering mechanism, as this is the dominant energy loss mechanism at room temperature. Equating the power gained from the field with that lost through scattering, we demonstrate that beyond a critical electric field, 114 kV/cm at T = 300 K, the power gained from the field exceeds that lost due to polar optical phonon scattering. This polar optical phonon instability leads to a dramatic increase in the electron energy, this being responsible for the onset of intervalley transitions. The predictions of our analytical model are compared with those of Monte Carlo simulations, and are found to be in satisfactory agreement.

scholarly journals Low-frequency optical phonon modes and carrier mobility in the halide perovskite CH3NH3PbBr3 using terahertz time-domain spectroscopy

2017 ◽  
Vol 111 (20) ◽  
pp. 201903 ◽  
Author(s):  
Daming Zhao ◽  
Jonathan M. Skelton ◽  
Hongwei Hu ◽  
Chan La-o-vorakiat ◽  
Jian-Xin Zhu ◽  
...  
Keyword(s):  
Time Domain ◽  
Optical Phonon ◽  
Carrier Mobility ◽  
Low Frequency ◽  
Terahertz Time Domain Spectroscopy ◽  
Phonon Modes ◽  
Time Domain Spectroscopy ◽  
Halide Perovskite

Brillouin Precursors from Magnon and Optical Phonon Polaritons from a Random-Walk Media

Optik ◽  
2021 ◽  
pp. 167520
Author(s):  
Robert R. Alfano ◽  
Yury Budansky ◽  
Lisa Chan ◽  
Richard Brun ◽  
Stewart Russell ◽  
...  
Keyword(s):  
Random Walk ◽  
Optical Phonon ◽  
Phonon Polaritons

Electron-Phonon Interaction and Joule Heating in Nanostructures

2008 ◽  
Author(s):  
Eric Pop
Keyword(s):  
Carbon Nanotubes ◽  
Electric Fields ◽  
Joule Heating ◽  
Optical Phonon ◽  
Phonon Transport ◽  
Phonon Energy ◽  
Strained Silicon ◽  
Vibrational Modes ◽  
Optical Phonons ◽  
Ambient Gas

The electron-phonon energy dissipation bottleneck is examined in silicon and carbon nanoscale devices. Monte Carlo simulations of Joule heating are used to investigate the spectrum of phonon emission in bulk and strained silicon. The generated phonon distributions are highly non-uniform in energy and momentum, although they can be approximately grouped into one third acoustic (AC) and two thirds optical phonons (OP) at high electric fields. The phonon dissipation is markedly different in strained silicon at low electric fields, where certain relaxation mechanisms are blocked by scattering selection rules. In very short (∼10 nm) silicon devices, electron and phonon transport is quasi-ballistic, and the heat generation domain is much displaced from the active device region, into the contact electrodes. The electron-phonon bottleneck is more severe in carbon nanotubes, where the optical phonon energy is three times higher than in silicon, and the electron-OP interaction is entirely dominant at high fields. Thus, persistent hot optical phonons are easily generated under Joule heating in single-walled carbon nanotubes suspended between two electrodes, in vacuum. This leads to negative differential conductance at high bias, light emission, and eventual breakdown. Conversely, optical and electrical measurements on such nanotubes can be used to gauge their thermal properties. The hot optical phonon effects appear less pronounced in suspended nanotubes immersed in an ambient gas, suggesting that phonons find relaxation pathways with the vibrational modes of the ambient gas molecules. Finally, hot optical phonons are least pronounced for carbon nanotube devices lying on dielectrics, where the OP modes can couple into the vibrational modes of the substrate. Such measurements and modeling suggest very interesting, non-equilibrium coupling between electrons and phonons in solid-state devices at nanometer length and picoseconds time scales.

Ultrafast Electron−Optical Phonon Scattering and Quasiparticle Lifetime in CVD-Grown Graphene

ACS Nano ◽  
2011 ◽  
Vol 5 (4) ◽  
pp. 3278-3283 ◽  
Author(s):  
Jingzhi Shang ◽  
Ting Yu ◽  
Jianyi Lin ◽  
Gagik G. Gurzadyan
Keyword(s):  
Optical Phonon ◽  
Phonon Scattering ◽  
Optical Phonon Scattering ◽  
Quasiparticle Lifetime ◽  
Grown Graphene
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