Sentences with word «phonon»

The interdisciplinary team of researchers, led by Alexander Balandin, distinguished professor of electrical and computer engineering, used ultraviolet Raman spectroscopy to investigate how spin ordering affects the energies of phonons in these materials.

The transport of heat in amorphous silicon is determined by the behavior of phonons in the material.

«The next step will be investigation of the spin - phonon interaction in nanoscale thin films and structures made of this important antiferromagnetic material.»

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

Practical applications of spintronic devices in information processing require accurate knowledge of the strength of the electron spin interaction with phonons.

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.

Someday, computers might store information using not only electric charges or magnetism, but also tiny packets of heat called phonons.

The thermal conductivity of both metals and insulators goes up as the ambient temperature goes down, and waay up as temperatures fall below 100K (There are reasons physicists prefer K, and the characteristic temperature of materials, theta Debye, which figures in phonon heat transport is one of them.)

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

Resume: Nanoscale phononic crystals can be used in many areas including high - frequency signal processing and the control of thermal phonons.

Despite their fundamental importance, accurate measurements of acoustic phonon lifetimes are challenging and their values are still unknown for most materials.

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].

Each dot absorbs and concentrates a laser's heat, which then flows through the underlying material as phonons.

Unlike conventional transistors, thermal transistors would not require the use of silicon, are based on phonons rather than electrons and might make use of the large amount of waste heat that is already generated in most practical electronics, said Chen.

«The lower the number of non-hexagonal rings in the junction (for example three octagons versus six heptagons), the lower the number of undesirable rings and thus lower phonon scattering and improved thermal transport.»

Despite the important application interest, there are few theoretical work on the physical properties of the MnGe compounds, and especially for phonon transport properties.

Recent research has focused on the possibility of using interference effects in phonon waves to control heat transport in materials.

If even a small amount of energy from phonons (the sound units that carry the energy through the germanium or silicon, much as photons are the units of light) hit the detector, it can be enough to make the device lose superconductivity and register a potential dark matter event through a device called a superconducting quantum interference device, or SQUID.

Scientists can accurately predict the thermal conductivity of many crystalline materials using expressions based on the widely - used «phonon gas model.»

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»

Although with the proper stimulation the same glass rod can amplify a variety of sounds — glass is made up of a jumble of silica molecules with a wide range of bonds, which can absorb and release phonons of many different frequencies — it can amplify just one frequency at a time.

By varying the size of heat sources, Chen and his colleagues can map out how far phonons travel between collisions, and how much they contribute to heat conduction.

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.

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.

«What we found is that this particular phonon mode is the one that's unstable, that «freezes,»» Delaire said.

The particles of light, called phonon polaritons, disobey standard laws of reflection as they bounce through the granules, but their movement isn't random.

Michael studied how phonons interact with electrons.

In their experiments, an optical pump pulse centered at 800 nm excites via impulsive Raman scattering a coherent optical phonon with Ag symmetry [movie].

The simulations of phonon dispersions, when plugged into software developed by the team, showed good agreement with the neutron scattering measurements taken at the SNS and HFIR by co-lead author Chen Li, also a postdoctoral fellow on Delaire's team.

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

Paul Birch says «Look, if phonons confuse you, forget the solid wire.

The triangular structure must be tiny in width to make possible the «lateral confinement» of phonons needed for the effect.

Heat travels through a material via phonons, quantized units of vibration that act as heat - carrying particles.

• Confined phonons could help create better electronic circuits (Nov 2016) • Heat conduction goes ballistic in opals (Apr 2016) • Bacterial DNA sequencing could help design «friendlier» nanoparticles (Jan 2015) • Optical traps feel the heat (Mar 2018)

Although his device can not yet pick up individual phonons, Delsing says his team is getting close: They can measure sound waves just a few quintillionths of a meter high.

They determined that having fewer rings in the junctions between nanotubes and graphene meant less scattering of heat - carrying phonons, which kept them onboard for the bumpy ride.

When co-author Zhaoming Zhu, Gauthier's postdoctoral research associate, encoded information onto one of these beams, the data could be imprinted on these newly created phonons and retained for 12 billionths of a second, long enough to be transferred back to light again by shining a third laser through the fiber.

«New tool measures distance between phonon collisions.»

That is the atomic mechanism behind the freezing in of this particular phonon mode.»

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.

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

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.

Phonons thus can't carry heat across a porous material as efficiently, giving the material a low thermal conductivity, which turns out to increase the efficiency of heat - to - electricity conversion.

Michael's research showed how electrons absorb and emit phonons when bombarded by sound waves.

In these cases, such phonons do not contribute much to a material's thermal conductivity.

Logical operations using phonons to switch, amplify and route signals can be realized by nanoscaling.

Researchers at the SHINES center showed that they could control phonons by confining them in a field of nanowires.

Although its crystal structure is stable, frozen - phonon calculations show that the TO mode is very soft and its frequency near the Brillouin zone centre decreases with decreasing temperature.