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sinayu71
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Hi guys:
Why people consider the plasmon ocsilation as a longitudinal wave?
Thank you for your answer.
sinayu
Why people consider the plasmon ocsilation as a longitudinal wave?
Thank you for your answer.
sinayu
fresnelspot said:because when you have the dielectric constant zero in the solid you examine , that means the solid does not react with E field .
fresnelspot said:because when you have the dielectric constant zero in the solid you examine , that means the solid does not react with E field .
But isn't that always the case for free electrons in a metal or plasma or ... ?Then the free electrons inside that solid start to move the same way as a sound wawe. Their force is in the same direction with their amplitude. They move back and forwards and they have their amplitude in that direction.
Another way of expressing this is that: When you let (epsilon) be zero , you ignite the longitudinal branches of that solid. Thatswhy they are told to be longitudinal.
marlon said:Dielectric constant is zero in the solid you examine ? What solids respects that property ? Besides, what does this have to do with the OP's question ?
But isn't that always the case for free electrons in a metal or plasma or ... ?
Huh ?
I always though that plasmons arise because of the quantisation of plasma oscillations which are defined as periodic oscillations of charge density in conducting media such as plasmas or metals. Now, just think of how any charge density (by approximation free electrons) respond to the presence of an electrical field. Just think of Coulomb's law for that matter.
Isn't it much easier and clearer to answer the OP's question like that ?
marlon
marlon said:Dielectric constant is zero in the solid you examine ? What solids respects that property ? Besides, what does this have to do with the OP's question ?
If the field is strong enough that the electrons can be treated as free then one can write down an expression for the long wavelength dielectric constant asBut isn't that always the case for free electrons in a metal or plasma or ... ?
Huh ?
I always though that plasmons arise because of the quantisation of plasma oscillations ...
fresnelspot said:my fellow. I don't want to discuss it in the forum. Because it takes much time. If you send me your msn adress we can discuss more efficiently. Or i can clarify my thought
Please do, this is exactly what this forum is here for. I am very curious to read your answers to my questions because i did not understand anything of what you wrote as an asnwer to the OP.fresnelspot said:my fellow. I don't want to discuss it in the forum. Because it takes much time. If you send me your msn adress we can discuss more efficiently. Or i can clarify my thought
olgranpappy said:The dielectric function tells us about how the system responds to an external perturbations. If we characterize the external perturbation by a frequency
[tex]\omega[/tex] and a wavenumber [tex]q[/tex] then it is only for a small subset of q and omega that the dielectric function is zero.
For example, in the case of q=0 (very (infinitely) long wavelength probe) the dielectric function happens to be zero when omega equal the so-called "plasma frequency" [tex]\Omega_{p}^2=4\pi e^2/m\frac{N}{V}[/tex] where e is the electric charge, m is the electron mass, N is the number of electrons, and V is the volume of the system.
In fact you are right. The plasmons are the quanta of plasma oscillations. In an ionic solid , The electrons are mobile and the nuclei are not. So it was modeled as a plasma. I answered the question in this way because the thread was " solid state" I thought He wanted to know about the plasmons in an ionic solid. But if you are not satisfied by the things tha we wrote i can suggest you " introduction to solid state physics" by Kittel . In this book the 10 th chapter is about polarons, polaritons and plasmons.marlon said:Please do, this is exactly what this forum is here for. I am very curious to read your answers to my questions because i did not understand anything of what you wrote as an asnwer to the OP.
Yes but how is this related to the definition of plasmons ? My point is, one does not need all the correct stuff you mention just to define plasmons.
regards
marlon
fresnelspot said:[blah]...i can't write the formulae here.
marlon said:Yes but how is this related to the definition of plasmons ? My point is, one does not need all the correct stuff...
olgranpappy said:The plasmon propagtor has a pole... where? You need to understand "all the correct stuff" to be able to interpret the meaning of the plasmon.
marlon said:I get your point and i agree with you. I just wanted to point out that we do not know the level of knowledge of the OP.
fresnelspot said:But if you are not satisfied by the things tha we wrote i can suggest you " introduction to solid state physics" by Kittel . In this book the 10 th chapter is about polarons, polaritons and plasmons.
Yes you can, use the tex-format : [tex]\int f^2(x)dx[/tex]because i can't write the formulae here.
marlon said:Ok, well actually i have that book so that is really nice for both of us...
Anyways, i don't get the "because when you have the dielectric constant zero in the solid you examine , that means the solid does not react with E field "-part because the solid as a whole DOES react with the E-field. Actually, it is that interaction (free electrons vibrate simultaneously along with the E-field) that generates the plasma oscillations.
Yes you can, use the tex-format : [tex]\int f^2(x)dx[/tex]
marlon
marlon said:Ok, well actually i have that book so that is really nice for both of us...
Anyways, i don't get the "because when you have the dielectric constant zero in the solid you examine , that means the solid does not react with E field "-part because the solid as a whole DOES react with the E-field. Actually, it is that interaction (free electrons vibrate simultaneously along with the E-field) that generates the plasma oscillations.
Yes you can, use the tex-format : [tex]\int f^2(x)dx[/tex]
marlon
Longitudinal waves are a type of mechanical wave that involves the oscillation of particles in the same direction as the wave is traveling.
Plasmon oscillations are collective oscillations of electrons in a material. They are considered longitudinal waves because the oscillation of the electrons is in the same direction as the wave is traveling.
Plasmon oscillations play a crucial role in determining the optical and electronic properties of materials. They can also be used in various applications such as sensing, energy conversion, and data storage.
Unlike other types of waves, such as electromagnetic waves, plasmon oscillations require a medium to propagate. They also have a much smaller wavelength and can interact with light at the nanoscale.
Surface plasmons are a type of plasmon oscillation that occurs at the interface between a metal and a dielectric material. They are generated by the interaction between light and the free electrons on the metal surface, and their properties are highly dependent on the material and geometry of the interface.