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Mar
13
comment Superconductivity in graphene with spin orbital coupling, is it proper to let the order parameter on two sub-lattice equal?
I think there is a reason why they do not use this term in the article. To some extent it is. Maybe.
Apr
24
comment Why does silicon have an indirect gap?
There is no intuitive explanation of experimental facts like this one. Actually, this is hard to get even from first-principle calculations.
Apr
24
comment Flux Quanta in the Arahanov-Bohm effect
@ramanujan_dirac By gauge I mean the choice of the vector potential.
Apr
23
comment Newton's Second Law Equivalent in rotational dynamics
This does not provide an answer to the question. To critique or request clarification from an author, leave a comment below their post - you can always comment on your own posts, and once you have sufficient reputation you will be able to comment on any post.
Mar
29
comment Semi-conductors
By definition? I mean, number of electrons is exactly the number given by FD statistics.
Feb
14
comment Would a laser with four possible energy levels be better than three?
What you mentioned is correct for three-level scheme. What is the advantage of fourth level?
Feb
11
comment The difference between the Wannier function and atomic orbit in a tight binding model
My comment is not against DFT. And technically your answer is more or less correct. It just looks strange when something relatively simple is explained using something much more complicated.
Feb
11
comment The difference between the Wannier function and atomic orbit in a tight binding model
It is quite strange that you are trying to explain what Wannier functions are by using arguments from DFT. DFT itself is an approximation which fails in many cases.
Feb
3
comment How can electrons be confined in Quantum dots?
And where is the question?
Feb
3
comment If photon energies are continuous and atomic energy levels are discrete, how can atoms absorb photons?
@user1104 I suppose I should clarify my comment. If you ask "why perpetual motion" is impossible? And someone answers "because it violates energy conservation" and you in turn ask "how exactly" the next answer will be "it depends on details". The same situation here. I gave you general answer and can not go into details if you want to stay general. The details of the level broadening depend on the details of the system. Most likely, it is interaction with the surrounding of the atom.
Feb
3
comment If photon energies are continuous and atomic energy levels are discrete, how can atoms absorb photons?
It can not. The details of how exactly is "goes into a discrete state" are important.
Jan
26
comment Why do the drift and diffusion components cancel for each type of carrier if EHP generation plays such big role in p-n-junctions?
I see no mention of zero bias in the question. And even for zero bias photoexcited carriers generated inside p-n junction will give you non-zero total current (which means that components are not compensated). That's how photodiode works.
Jan
25
comment Why do the drift and diffusion components cancel for each type of carrier if EHP generation plays such big role in p-n-junctions?
Your first sentence is nonsense. If drift and diffusion components cancel each other, the current through p-n junction is zero and diode has infinite resistivity. Which contradicts the facts. It seems that your question is incomplete: you mean no bias, or some other conditions?
Jan
15
comment Is all matter made of virtual particles?
It is much,much more complicated than stated in the article. So much that the main article line is completely wrong.
Jan
10
comment How creation of point defects in semiconductors is affected by strain?
I am interested in the regime when no dislocations appear in the system. And no, there are no dislocations in the system. At least, their number is negligible.
Jan
9
comment How creation of point defects in semiconductors is affected by strain?
I'll take a look, but the titles make me think that not much about point defects is discussed there.
Sep
15
comment How to prove that proper orthochronous Lorentz transformations form a group?
@vtt Wrong idea is that non-associative value may be associated with any transformation. Normally, one expects that the phrase "First I apply transform A then B and then C" may be expressed mathematically. For non-associative operations however that would mean undefined result as long as two variants of brackets are possible. That's why it is not a good idea to use non-associative value for transformations (or coordinate change or similar).
Sep
15
comment How to prove that proper orthochronous Lorentz transformations form a group?
@Karsus Ren sorry, I have no time to write the whole stuff. Are you satisfied with Qmechanic answer? He did an excellent job writing this in details.
Sep
15
comment How to prove that proper orthochronous Lorentz transformations form a group?
@vtt Magmas, loops and others may be constructive to use sometimes, somewhere for something which is not physical transform/coordinate change/etc. You have a wrong idea of what associativity means.
Sep
14
comment How to prove that proper orthochronous Lorentz transformations form a group?
Extend your question and I will extend my answer. I see two ways 1) All elements may be represented as a product of basis boost and rotations. The closure is obvious for them. 2) Do some linear algebra. Which way you prefer?