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A phonon is a collective vibrational mode in an ideal crystalline solid.
A single phonon is pure vibrational mode. It is direct analogy to a pure vibrational mode in a musical instrument such as a string of a guitar.
It can be said that it is a sound wave, but the vibrations allowed that are pure single mode vibrations are more extensive than simple sound waves.
Phonons, in their original and normal sense, occur in perfect crystalline structures where each atom has a specific equilibrium location that is repeated regularly in space.
In a pure single phonon mode there is a periodic vibration (i.e. displacement) of each atom that is described as a sinusoidal variation in space and time. One specifies a particular phonon with a wavelength, direction and frequency, just as with a sound wave.
In real solids, there are imperfections, but they are near enough to idea that the idealized concept of a phonon is usually completely adequate.
Finally, phonons can be described as classical vibrations as is natural in classical mechanics and they can be described as quantum vibrations using quantum mechanics. The quantum description is fundamentally correct, but the classical description is very useful and convenient in many cases. Some people would say that you should not call the collective vibrations of a solid phonons unless you are describing them as a quantum phenomena but other people would say that is too picky. Usually, however, the term phonon implies that quantum nature of the vibration of a crystal.
Wiki User
∙ 11y ago
Wiki User
∙ 11y agoThe phonon effect is the name given to pseudo particle which transmits vibrational kinetic energy through a medium. Vibrations caused by thermal energy within a crystal lattice cause phonon generation, and electron-phonon interactions are the primary cause of electrical resistance in metals. The phonon can also be viewed as a wave phenomenon when vibrations are emitted from a physical source, rather than a thermal source. If the medium for these phonon waves is air or water, it is typically referred to as sound, thereby explaining the root "phon" from the greek word for sound "phonos."
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What is the difference between electron-phonon and phonon-electron interaction?
Basic Answer: The terms "electron-phonon interaction" and "phonon-electron interaction" mean the same thing and one almost always hears the former and not the latter. In a nutshell the term refers to the fact that the usual idea of separating the quantum system of electrons and the quantum system of vibrations (phonons) is an approximation that does not answer questions about the exchange of energy between the two systems. The next most sophisticated treatment involves including a term in the Hamiltonian that approximates the mechanism for that energy exchange. That term is called the electron-phonon interaction term. Addendum on Electron-Phonon Interaction: If the question were posed asking to explain the electron-phonon interaction, this answer would have to discuss the process of calculating electronic energies for fixed nuclei and then solving the problem where the nuclei are allowed to move within the adiabatic approximation. That leads to the two quantum systems mentioned above and thus to the need for an improvement which treats electrons and nuclei both being treated at the same time in a quantum mechanical fashion. One proceeds with an electronic Hamiltonian and a nuclear coordinate Hamiltonian and adds a third term called the electron-phonon interaction which is meant to be a good approximation to the full quantum system and is amenable to reasonable approximation methods.
Why some phonons are called optical phonon?
Optical phonons are phonon polarization modes with a minimum frequency, regardless of wavelength, which occur in crystals with more than one atom per primitive cell. Primitive cell is the early technological development....
The apparent curving of the winds is called?
the Coriolis effect
What are the benificial effect?
benificial effect
What effect does lithium have on thyroid gland?
no effect.
What is the smallest unit of sound wave energy?
The smallest unit of sound wave energy is the phonon. The phonon and the photon and the electron can in some ways all behave like a small particle.
What is the difference between electron-phonon and phonon-electron interaction?
Basic Answer: The terms "electron-phonon interaction" and "phonon-electron interaction" mean the same thing and one almost always hears the former and not the latter. In a nutshell the term refers to the fact that the usual idea of separating the quantum system of electrons and the quantum system of vibrations (phonons) is an approximation that does not answer questions about the exchange of energy between the two systems. The next most sophisticated treatment involves including a term in the Hamiltonian that approximates the mechanism for that energy exchange. That term is called the electron-phonon interaction term. Addendum on Electron-Phonon Interaction: If the question were posed asking to explain the electron-phonon interaction, this answer would have to discuss the process of calculating electronic energies for fixed nuclei and then solving the problem where the nuclei are allowed to move within the adiabatic approximation. That leads to the two quantum systems mentioned above and thus to the need for an improvement which treats electrons and nuclei both being treated at the same time in a quantum mechanical fashion. One proceeds with an electronic Hamiltonian and a nuclear coordinate Hamiltonian and adds a third term called the electron-phonon interaction which is meant to be a good approximation to the full quantum system and is amenable to reasonable approximation methods.
What is phonon theory?
sound and other mechanical vibrations are quantized as bosonic particles called phonons.
How did Persephone get her name?
Source from Wikipedia:It can be derived from "φέρειν φόνον", pherein phonon, "to bring (or cause) death".
Why some phonons are called optical phonon?
Optical phonons are phonon polarization modes with a minimum frequency, regardless of wavelength, which occur in crystals with more than one atom per primitive cell. Primitive cell is the early technological development....
What happens when electrons in conduction band loses its energy and falls to a hole in the valence band?
The energy leaves as either a photon or phonon.
What has the author Lloyd W Root written?
Lloyd W. Root has written: 'Phonon attenuation characteristics of manganous oxide (MnO)'
What has the author R J Nicholas written?
R. J. Nicholas has written: 'The magnetophonon effect' -- subject(s): Phonons, Electron-phonon interactions
What has the author Mark John Smith written?
Mark John Smith has written: 'Low temperature phonon-drag thermoelectric power calculations in GaAs/GaAlAs heterojunctions and Si MOSFETs'
What has the author Jay Charles Hicks written?
Jay Charles Hicks has written: 'Electron-phonon contribution to the electronic density of states in a dilute alloy' -- subject- s -: Alloys, Analysis
What has the author Melanie L Ledgerwood written?
Melanie L. Ledgerwood has written: 'Phonon dynamics and self-energy effects in highly photo-excited germanium' -- subject(s): Physics Theses 'Ultrashort period laser induced periodic surface structures' -- subject(s): Physics Theses
Which one has greater specific heat capacity a conductor or an insulator?
Well I am not an expert on this topic, but I did find something close to the answer to this. Here goes. The heat capacity of metals is a combination of the electronic contribution and the phonon contribution. The vibrations in the lattice give 3R to the heat capacity at high temperatures and something close to planck statistics as they approach the 'Debye Temperature' of about 100Kelvin. For Metals they have this T^3 term that is due to phonon heat capacity (which asymptotically approaches the value of 3R at temperatures above TDebye). But they also have a T^1 term that is due to the relationship between electrical conductivity and thermal conductivity. So the real question for you is, for the metal you are looking at, what is the temperature, and what are those coefficients of Cv=AT^1 + BT^3. If you find those, you can answer your question.
