When the incident frequency is equal to the plasmon frequency, there is occurrence of resonance. In such condition, maximum energy transfer takes place owing to resonance coupling. Regarding fronhlic mode in the dispersion relation, please go through these articles.

Fröhlich modes in porous III-V semiconductors by Sarua et al., 2001 in J of Physics (IOP)

Theory of the weakly pinned Fröhlich mode by W Wonneberger in Synthetic Metals, 1991.

Hope this will be useful for you.

RB

When the incident frequency is equal to the plasmon frequency, there is occurrence of resonance. In such condition, maximum energy transfer takes place owing to resonance coupling. Regarding fronhlic mode in the dispersion relation, please go through these articles.

Fröhlich modes in porous III-V semiconductors by Sarua et al., 2001 in J of Physics (IOP)

Theory of the weakly pinned Fröhlich mode by W Wonneberger in Synthetic Metals, 1991.

Hope this will be useful for you.

RB

Thank you very much! I am curious about the form of transfered energy from photons. does it be absorbed by electrons mostly so that the electrons colliding with defects transfer into heat?

Hello Yen Chi Chung,

Even though there's no defect inside the metal, the energy will still dissipate (intrinsic ohmic loss). When the electrons collide with ions in the metal, they are scattered; the direction of electron's motion will becomes random, so the energy from the electrical field will transform to thermal energy.[1] And yes! If there are some defect that electrons colloids on , the energy will transfer into heat.

[1] https://www.electrical4u.com/drift-velocity-drift-current-and-electron-mobility/

In the reality, Is there really no defects in the metal? Because I also did some research of defects in metal. There is a paper discussing the defects in pure metal. I am a little bit confused. And another question is that if the incident energy absorbed from photons is mostly transferred into thermal energy. In other words, do we see the least reflection of light scattered from the metal surface?

The paper:http://www.sciencedirect.com/science/article/pii/0502820559900176

In reality, I would say it is hard to exclude defects inside the bulk. The defects will depends on your crystallization method. For example, the quality of colloidal metals will have less grain boundary inside the bulk. For your second question, do you mean " least reflection from the metal surface? "? If so, I would say yes! A near unity absorption material (ex. Vantablack ,Wikipedia ) would not reflect any lights, and the photon energy will transfer into thermal energy.

p.s. Reflection and scattering are different concept.

Processes of photons' energy dissipation have many components. Part of it is transferred into heat due to ohmic losses in metal during oscillation of electron plasma density, but some of surface plasmon-polaritons (SPPs) will interact with surface defects and as result they can be either transferred into another SPPs with different direction of propagation, or they can be transferred back into bulk propagating photons, this is scattered light, or due to inelastic interaction with defect, their energy can be transferred into ions' movement, into heat. Those processes (excepting heat transfer) can be repeated several times.