Sentences with phrase «phonon anharmonicity»

But GaAs with its 1.47 eV bandgap readily emits 844 nm photons, which is the bandgap photon energy, because it is a direct gap semiconductor, and that transition is allowed, without any momentum discrepancy, requiring a phonon interraction as well.

UNDER NIGHT IN - BIRTH Exe: Late [st] features a fairly meaty case of twenty characters, four of which are completely new (Phonon, Wagner, Mika and Enkidu).

Choose from 20 unique characters, from series veterans like Hyde, Merkava, and Linne to one of the four newly - introduced characters (Phonon, Mika, Wagner and Enkidu) and unleash their power!

Phonon, Impulsonic's flagship product, allows the authoring of environmental audio effects like reverb, occlusion, and 3D positional audio by modeling the physics of sound.

Obviously, being able to play as Phonon, Mika, Wagner, and Enkidu and experience a much more fleshed out story is cool but the game as a whole doesn't feel all that different.

The difference in the neutron's energy before and after the collision is equal to the phonon energy.

Links BibTeX Tags: metallic glass, neutron, phase transition, phonon, thermodynamics, vibrational entropy

In solids, sounds and heat are entangled in the form of a quasiparticle called a phonon.

The scientists induced vibrations in the diamonds, creating a phonon, and showed that it was shared between them even though they were separated by a distance of about 15 centimeters — definitely a measurement in the macro world («spooky action at a distance,» as Einstein put it).

Dresselhaus has investigated this very fundamental electron — phonon interaction in nanostructures using the powerful techniques of Raman and Resonance Raman spectroscopy.

Our results, together with experimental measurements of the phonon dispersion curve, allow us to predict the nature of the droplet.

Resulting from the special sp orbital hybridization mediated by the Ga - d orbital in ML GaN, the strongly polarized Ga — N bond, localized charge density, and its inhomogeneous distribution induce large phonon anharmonicity and lead to the intrinsic low κ of ML GaN.

Ab Initio Calculations of Nonequilibrium Coupled Carrier and Phonon Dynamics.

It is shown that the acoustic phonon lifetimes can be tuned both by strain engineering of the suspended structures and strain modification by temperature variation in addition to a strong dependence on the thickness of the suspended structures [1].

Calculation of Phonon transport through molecular junctions between graphene sheets via Green's functions technique through DFTB

We find that the divergence of the thermal expansion coefficients near the phase transition in GeTe is induced by acoustic phonon coupling to soft TO modes.

In this talk, I will show, however, the wave effects on heat conduction can be observed and exploited to manipulate phonon heat conduction.

The combination of temperature dependent micro-Raman and femtosecond reflectivity measurements allows for a complete decoupling of the effects of temperature, geometry, and strain on the acoustic phonon dynamics [2, 3].

We show further that phonon heat conduction localization happens in GaAs / AlAs superlattice by placing ErAs nanodots at interfaces.

Phonon properties have been studied by Green's functions phonon transport method through Density Functional based Tight Binding theory, implemented into DFTB package.

Systematic analysis is performed based on the study of the contribution from phonon branches, comparison among the mode level phonon group velocity and lifetime, the detailed process and channels of phonon — phonon scattering, and phonon anharmonicity with potential energy well.

Accessing the coherent heat conduction regime opens a new venue for phonon engineering.

In this work, a harmonic lattice dynamics and scattering boundary method based atomistic modeling tool was created to calculate phonon spectra and modal phonon transmission coefficients in nano - phononic structures and diameter - modulated nanowires.

We found that, different from graphene and ML BN, the phonon — phonon scattering selection rule in 2D GaN is slightly broken by the lowered symmetry due to the large difference in the atomic radius and mass between Ga and N atoms.

In superlattice structures, ballistic phonon transport across the whole thickness of the superlattices implies phase coherence.

The latest investigations on the thermal properties of silicon, the most common material in electronics, micro - and nano - electro - mechanical systems (MEMS and NEMS) and photonics, have pointed to nanostructuring as a highly efficient approach to acoustic phonon engineering [1 - 3].

In this paper, by solving the Boltzmann transport equation (BTE) based on first - principles calculations, we performed a comprehensive study of the phonon transport properties of ML GaN, with detailed comparison to bulk GaN, 2D graphene, silicene and ML BN with similar honeycomb structure.

However, the modal phonon transmission coefficients across these geometrically irregular nanostructures and the effect of nanostructure geometry on thermal transport has not been fully understood.

This paper addresses the phonon transport and the thermal conductance through a range of different molecular junctions, including alkyl chains with variable length, aliphatic - aromatic structures and polyaromatic junctions.

Even in the case of the extensively studied group IV semiconductors, measurements of phonon lifetimes are scarce and the impact of strain engineering is not well understood.

Resume: Although classical size effects on phonon heat conduction are now well - established and understood, manipulating phonon heat conduction via waves is still a dream to be realized due to the broadband and short wavelength nature of phonons.

Phonon Density of States (DOS) were computed by Molecular Dynamics for different regions in the structure.

Furthermore, the phonon transport in MnGe nanoinclusions embedded in Ge matrix and MnGe / Ge superlattices were also studied.

The capability to tune the acoustic phonon dynamics in technologically relevant group IV nanostructures provides a promising prospect to control the propagation of acoustic and thermal phonons with great implications on nanoscale hypersound and thermal transport.

In new neutron experiments conducted at the Institut Laue - Langevin (ILL) and the French National Centre for Scientific Research (CNRS), researchers have provided a direct quantitative measurement of phonon lifetimes in a clathrate, offering a novel picture of thermal conductivity in...

Although classical size effects on phonon heat conduction are now well - established and understood, manipulating phonon heat conduction via waves is still a dream to be realized due to the broadband and short wavelength nature of phonons.

Lattice thermal transport can be surpressed by phonon nesting, resonance, nanostructure, and etc..

Pure quartic phonon modes in scandium flouride stiffen at elevated temperature and large side motions of the flourine atoms pulls their neighbouring scandium atoms together.

A multi-partner study published today in Nature Communications has addressed phonon lifetime measurement challenges using inelastic neutron scattering (INS) and neutron resonant spin - echo (NRSE) experiments conducted at the Institut Laue Langevin (ILL) in Grenoble, and Laboratoire Léon Brillouin (LLB) Saclay, France.

The authors claim that «this work will make it possible to image the fastest charge, spin and phonon dynamics in functioning nanosystems in real space and time»

Whereas the «glass - like» thermal conductivity of the clathrate Ba7.81 Ge40.67 Au5.33 has frequently been associated with a short phonon lifetime, this study measured for the first time to date a very long phonon lifetime using a large single crystal sample of high quality.

Recent studies indicate that the stronger the spin - phonon interaction is, the more favorable it is in the development of new materials — such as a multiferroic material, for example — in which the coupling of magnetism and the lattice system has great importance.

«Phonon tunneling» explains heat flow across nanometer - wide gaps.»

«But it does capture the phonon and electron movements in frames shot 100 trillion times per second, and we can string about 100 of them together just like movie frames to get a full picture of how they are linked.»

Spin - phonon coupling directly represents the strength of interaction between magnetism (spin) and the crystal lattice system (phonon).

A research team led by Kazunari Yamaura, chief researcher, Superconducting Properties Unit, National Institute for Materials Science (NIMS), Japan, and Dr. Stuart Calder and others at the Oak Ridge National Laboratory in the United States, jointly demonstrated that the strongest ever spin - phonon coupling was observed in osmium oxide synthesized for the first time in the world by NIMS in 2009.

The fact that this structural characteristic is common to all platinum group elements suggests that compounds based on these elements other than osmium are also likely to be associated with strong spin - phonon coupling.

The strong spin - phonon coupling may be caused by the outermost orbitals of osmium atoms as they are greatly extended outward in space, in the solid oxide.

When they modeled heat flow between two sodium chloride lattices, the researchers found that heat flowed from one lattice to the other via phonon tunneling, at gaps of one nanometer and smaller.

For example, if an engineer desires a material with certain thermal properties, the mean free path distribution could serve as a blueprint to design specific «scattering centers» within the material — locations that prompt phonon collisions, in turn scattering heat propagation, leading to reduced heat carrying ability.