What is Plasmon: Definition and 35 Discussions

In physics, a plasmon is a quantum of plasma oscillation. Just as light (an optical oscillation) consists of photons, the plasma oscillation consists of plasmons. The plasmon can be considered as a quasiparticle since it arises from the quantization of plasma oscillations, just like phonons are quantizations of mechanical vibrations. Thus, plasmons are collective (a discrete number) oscillations of the free electron gas density. For example, at optical frequencies, plasmons can couple with a photon to create another quasiparticle called a plasmon polariton.

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  1. redirmigician

    I Can surface plasmons be used to build GeV gamma-ray lasers?

    I read a paper about coherent surface plasmon amplification by free electron pumping in an article a few days ago. It seems to work as some kind of free electron laser-like light source, and I wonder how high the energy of photons can go in this way. Also I read in another paper about...
  2. T

    Some questions about surface plasmon polaritons

    Hi there, To be clear, this is not a homework question, I am a graduate student reading about the use of plasmonics for biosensing. I felt I should post here instead of in the "general physics" forum since I do have questions, but they are more qualitative, nonetheless I will try to follow the...
  3. M

    A What is the bulk plasmon peak?

    When I read “Extraordinary optical transmission through sub-wavelength hole arrays”, I saw this figure but I don't get the bulk plasmon peak at 326 nm. What is the mean of bulk plasmon peak?
  4. GiovanniNunziante

    A Derivation of the Heisenberg equation for electron density

    I'm studying plasmons from "Haken-Quantum Field Theory of Solids", and i need some help in the calculation of the equation of motion of eletrons' density \begin{equation} \hat{\rho}_{\overrightarrow{q}} = \frac{1}{\sqrt{V}} \sum_{\overrightarrow{k}}...
  5. F

    A Localized plasmon and bulk plasmon on a nanoparticle

    As far as I have understood, surface plasmon can't be excited with natural light because the dispersion relation of the plasmon doesn't cross the vacuum dispersion relation of light. But, when we decrease the size (for example, we take a nanoparticle), we are now in quasistatic approximation...
  6. shishi

    Negative permittivity of metals – light-trapping and plasmon

    Negative permittivity of metals – The effect of light-trapping via plasmonics I’m trying to understand the effect of light-trapping by plasmonics (for example - Localized Surface Plasmon Resonance, Surface Plasmon Polariton, Scattered Plasmons), and how negative permittivity related to that...
  7. C

    A Fullerene confined metal particles and increasing pressure

    Hello, I would like to ask a question regarding possible change of orbital conformation of a fullerene particle filled with metal. Is there any basis to the assumption that for if you encase a metal, such as a round nanoparticle of lead cooled to minimal thermodynamical state, just so it fits...
  8. M

    Surface plasmon polaritons at metal / insulator interfaces

    Homework Statement Consider the metal-vacuum interface located at z = 0,the metal filling the entire half-space z ≥ 0, vacuum filling (!?) the half-space z < 0. The dielectric function in the metal in the long-wavelength limit is given by: where ε0 is the vacuum permittivity. In the metal a...
  9. C

    I What is the Plasmon Wave Size?

    Hello, Plasmons are waves formed by electron density fluctuations on a metallic surface. Basically once excited, they can propagate freely along a suitable metallic-dielectric surface, decaying relatively quickly. I'm interested in the y-axis component of the wave, perpendicular to the...
  10. P

    Localized surface plasmon resonance (LSPR)

    Hi! I wondering does anyone here has a clue of lowering the absorption level and narrowing the scattering bandwidth of LSPR of nanoparticles? Are those "intrinsic" properties or can be improved by modifying their size, shapes, etc? Thanks for sharing your thoughts! Paul
  11. H

    Why does the velocity of 2D plasmon diverge at small q?

    Now plasma represents collective wave-like motions of charged particles. In 3D, their frequency is well known to be almost a constant, ##\omega^{3D}_p \approx \sqrt{4\pi ne^2/m}## with n=charge density, m=particle mass. However, in 2D, one can show that it becomes ##\omega^{2D}_p \sim...
  12. I

    Surface plasmon dependence on surface area to volume ratio

    Hey everyone, I was recently reading a paper on surface enhanced Raman scattering, and it mentioned that plasmons (and for that matter surface plasmon polaritons-where my interest lies) are sensitive to the surface to volume ratio of the structure. I can begin to understand intuitively with...
  13. S

    Relationship between phonon and plasmon

    I am conducting an experiment on the parabolic trough that concentrates the solar light and heats up water. I am using different metal sheets (zinc, aluminium, copper, tin...) for the parabolic trough to see the differences in temperature change. I researched on a few things and I understand...
  14. A

    Is a surface plasmon an EM wave?

    From my understanding, surface plasmons (SPs) are oscillations of electrons caused by incident EM waves. A photon from the EM wave can couple with a plasmon to create a surface plasmon polariton (SPP). Some books/websites use the words SPP and SP interchangeably, so I am confused as to whether...
  15. G

    What techniques are used to make surface plasmon resonance chips?

    The chips used for surface plasmon resonance are fairly expensive. Does anyone know what nanofabrication techniques are used to make the chips? I've been told they are relatively easy to make if one has access to a nanoscale facility.
  16. S

    Longitudinal plasmon oscillation

    Kittel solid state physics book ( chapter 14)says when dielectric permittivity is zero, then longitudinal polarization wave possibly exists. It is hard to imagine how this is possible. Can anybody explain this? If the permittivity is zero, then there shouldn'n be any response, right? How come...
  17. E

    Polariton, polaron, plasmon and spaser

    Hello everyone! I would like to ask you for help on this: 1. what are the differences between polariton, polaron and plasmon? 2. such as theoretical aspects I have to know to understand the functioning of a spaser? (spaser=surface plasmon amplification by stimulated emission of radiation)...
  18. Z

    Surface Plasmon Polaritons at Metal / Insulator Interfaces

    Homework Statement we are considering the surface plasmon mode at the interface between a dielectric and a plasma. Solve explicitly for the TM mode and identify the relationship between dielectric and plasma permittivities that must be satisfied for the mode to exist. Homework Equations...
  19. S

    Surface plasmon magnetic field graphs - how were they determined?

    Can someone please explain how these graphs were obtained? There's no Hy in the equation given. Thanks in advance. http://snag.gy/utX7W.jpg
  20. mcodesmart

    Electron System Thermodynamics: Plasmon Energies 5-30eV

    I need an explantion of the following description of plasmon, "Plasmon energies in the range of 5-30eV for electron systems of metallic densities,consequently they play no role in determining the thermodynamic properties of the electron system." What kind of thermodynamic properties are...
  21. J

    Surface plasmon wavevector calculations

    I am trying to calculate the wavevector of a surface plasmon. The magnitude of the wavevector is given by: k = \frac{ω}{c}\sqrt{\frac{ε_1ε_2}{ε_1+ε_2}} where ε1 is the dielectric constant for air and ε2 is the dielectric constant for the metal. However, according to the Drude model, the...
  22. A

    What does it mean for a plasmon to confine or guide light?

    I'm trying to grasp the basic concepts of plasmons and can't quite picture what is going on. When light is incident on small metal nanoparticles, it causes the conduction electrons of the metal to oscillate at the frequency of the photon. Is that a plasmon? Is that also the same as it...
  23. P

    Why the surface plasmon always use gold or silver as a metal film?

    I found a lot the the surface plasmon on prism geometry are using gold for metal film, and part of it are using silver. Why we need use gold or sivler as a metal film, is it about the condutivity?
  24. TheFerruccio

    How one should excite Surface Plasmon Polaritons on a prism?

    I've got a red laser, goniometer for aligning the angles, photoreceptor that outputs values... I've got a right angle prism with a ~40nm gold coating on the diagonal, and I *should* be getting some sort of dip in the intensity at certain angles, as P-polarized EM waves should be absorbed into...
  25. S

    Can you explain the coupling of surface plasmons with photons?

    Hi everyone, I am trying to figure out what is the coupling of a surface plasmon with a photon for the generation of a surface plasmon polariton. In fact I don't understand what a coupling is in this context. Some texts say that for the coupling to happen is necessary that the dispersion...
  26. A

    Can the Plasmon Frequency in Metals Be Changed Experimentally?

    Hi guys; I have a question about the Plasmon frequencies in metals I know that it can be calculated as following: ωp2=Ne2/ε0meff I was just wondering if anyone knows it is possible to change the plasmon frequency of any metal let say silver experimentally or not. I am working on metallic...
  27. S

    Plasmon Energy Storage: Limitations & Possibilities

    As I know main limitation of superconducting energy storage is Lorentz forces which are created by magnetic field and ultimately destroy a superconducting ring. But there exist so called plasmon waves or plasma waves which could spread in metals and plasma. If I no make mistake they don't...
  28. M

    Plasmon vs Electrical Wave: Difference Explained

    What's the difference between a plasmon and the wave that propagates through a wire when you flip a light switch?
  29. A

    Surface plasmon, Fresnel's equations

    I'm writing a school paper on surface plasmons (as I said in another post), and among other things, I'm supposed to deduce Fresnel's equations for p-polarized light (that is, the ratios \frac{E_{0r}}{E_{0i}}=\frac{a}{b} and \frac{E_0t}{E_0i}=\frac{c}{b}). Now, apparently, when a surface plasmon...
  30. P

    Surface Plasmon Resonance in Gold Films: My Conundrum

    I'm trying understand surface plasmon resonance in a gold film, and have decided that gold must have a refractive index of say 5-10ish in optical light. However I'm not sure and I think I might be on the wrong track. Also does negative refractive index have anything to do with surface plasmon...
  31. R

    Introduction to Plasmon Physics & Its Effects

    hi everyone, i am doing a research on plasmonics and surface plasmonic effects in heating nano materials using em waves... can you suggest me any resources otherthan wikipedia where i can get an introduction to all this...please suggest me a source which is simple to understand... also is...
  32. P

    Surface Plasmon Explained - Get the Answers!

    surface plasmon?? hi Can anyone explain to me what's the surface plasmon? thanks
  33. S

    Why is a plasmon ocsilation considered a longitudinal wave?

    Hi guys: Why people consider the plasmon ocsilation as a longitudinal wave? Thank you for your answer. sinayu
  34. I

    How Does Effective Mass Affect Plasmon Dispersion in Tetragonal Crystals?

    I need help with a problem in solid state physics: Find the dispersion relation of long-wavelength plasmons in a simple tetragonal crystal in the case of almost empty band built of s-type orbitals. What happens in the case when m_{xx} << m_{zz} ? This is what I did for now (with some help...