Recent content by NaOH

Raman processes are rather rare events (compared to the Rayleigh peak), with, in general, Stokes scattering occurring more often than Anti-Stokes events. This leads to instrumentation that uses the Stokes "regime" to collect data. Not really a source, but nevertheless some resource...

I can't help you any further. What I can say is that the book mentions the form of wavefunction for traveling waves, for another the Bloch function is a (travelling) plane wave.

Introduction of Solid State Physics, charles kittel. Look under bloch functions

The difference between them and free electron is effective mass. In solids, you must understand that bulk properties are usually not the result of each single electron minding their own business but rather the effect of the collection of all their properties. Since the electrons are still...

I don't have any knowledge in area this but maybe this link will help? In particular, it mentions that for elastic materials it does not dissipate energy, but visco-elastic materials do.

Consider an Oxygen molecule. The outermost electrons are moving. Electrons don't simply stop because they participate in chemical bonds. A crystal can be very crudely described as a very very large molecule. The electrons here then are shared (and thus moving) throughout this whole collection...

To understand this you need another piece of knowledge which is not found in your typical band diagram -- that of (crystal) momentum. Associated with each energy state is a certain (crystal) momentum. This momentum is what allows the net movement of electrons, which we measure as current. When...

I did not mean to imply that two electrons occupy the same state. I am saying that the electron is spread throughout the whole solid. However, as we move along the crystal and we are still talking about the same electron (and thus state), the line is diagrammatically shown to be horizontal. The...

The same energy state is extended throughout the solid, in other words, the electron wave is spread throughout the whole solid.

The energy states are spread throughout the whole solid. So each horizontal line represents the same state.

So I guess I should wrap things up with the math. The creation operator of a one phonon state is: $$\sum_{k} c_{k}a^{\dagger}$$ This means that one phonon, in general, is a superposition of pure phonon states which are the eigenstates of the normal mode. This would mean that the scattering...

My concern with a wide energy space is that ultimately, I want to reconcile with spectroscopy and this will not allow me to observe the absorption peaks! However, I suppose that I can find comfort that with an incident electric field that can drive for sufficiently long, the energy spectrum...

Yes, my understanding of phonons is quite limited and in most undergrad texts, the phonon that are introduced only mention the kind which extend over the whole crystal. Where can I find more description about these "localised phonons"?

Thanks for the replies. The second quantization formalism is a wonderful way to view this, but I have avoided referring to it in the topic post because I wanted a classical picture as well. Piecing together the replies, is the following statement how I should interprete the scattering process...

Yes, your calculation seems correct, but a few things to consider: 1) You might want to check the math again. I obtained 16.168 kJ/mol. The discrepancy might be because you approximated the value to be 600J/kg. 2) From wikipedia, we have: So, if this is one way to convert if you have good...