Recent content by rogdal

Ah, I see. I thought the exercise was meant to obtain a well defined expression of ##\vec{B}## in terms of the Bohr magneton. Thanks!

But if I did what you say I'd have, for instance, ##\vec{r}=(1,0,0)##. Then the total magnetic field would be: $$\vec{B}=\frac{\mu_0}{4\pi}\left(3(\mu\cos{\theta})\hat{u_x}-\vec{\mu}\right)$$ Since ##|\vec{r}|=1##. But this expression cannot be simplified because we don't know what the...

Really? Well, in reality I worry about the direction of the dipole that is causing the magnetic field, i.e., the one in the origin of coordinates. Wouldn't its direction influence the product ##\vec{\mu}·\vec{r}##?

I'm having a bit of trouble with this exercise because, even if I understand the physics of the dipole-dipole interaction in an ideal classical system, I don't get to know how to approach this problem. I've got a few doubts about how this system would work. First of all, what would be the...

Thanks, all the articles I've referenced provide semiempirical results for the parameters, but how can they differ that much from each other? I mean, if the parameters at Table 4 were taken at T = 0 K, Delta_a very similar to the one provided in Datta's book, but Delta_c differs in one order of...

I'm simulating on code the tight-binding sp3s* bandstructure of certain semiconductors, such as GaAs, AlP, InP, ZnSe, etc. with spin-orbit coupling at a temperature of T = 0 K but I'm having trouble at finding the corresponding spin-orbit splitting parameters. For example, I've found in this...

Thank you very much, @TSny, I understand it now. Yes, I've shown both flux differentials and then the final answer is straightforward.

Thanks for your answer. Yes, sorry, the MB distribution in 2 dimensions is $$\rho(\vec{p})=\frac{1}{2\pi m k_B T}e^{-\frac{p^2}{2mk_B T}}$$ I forgot to square the p above. But the rest of the conclusions were obtained with the correct form of the 2D MB distributions. Do you know how to come up...

I could not find any derivations in the litterature, except for the expected value of the energy flux expression itself: $$\overline{\Phi_{effusion,\epsilon}} = \overline{\dot{N_{ef}}}\overline{\epsilon_{ef}}=\frac{3Nl}{2A}\sqrt{\frac{(k_BT)^3}{2\pi m}}$$ I've started off by calculating the...

Oh, I see... Many thanks @TSny and @vela for your help. I understand it now!

Hello @TSny. Many thanks for your answer. Yes, obviously, after thinking it a bit, the argument I used in my 2nd scenario for justifying the origin of the 2 extra factor makes no sense. Let me try to think about the probability distributions from your interpretations: (1) In this case, we...

I have considered two scenarios: 1) A particle that has just collided with the wall at ##z=L## is moving with a velocity ##v_z<0## moving away from the wall. Hence, the probability that this particle has of colliding again is ##0##, so its distribution is also ##0##. 2) A particle moving with...

TL;DR Summary: Given a pentaquark: (a) Determine the isospin multiplet it belongs to. (b) Calculate a kind of a Gottfried Sum Rule for this pentaquark-neutrino or -antineutrino scattering. Hello everybody, I'm having a bit of a trouble with the exercise below as it deals with a pentaquark and...

Good morning, I am developing an experiment on how to study the kinetics of etching/erasure of holographic lattices in a photorefractive material and I have some doubts about the procedure to follow. I have a single-mode He-Ne laser with monochromatic light of wavelength 632.8 nm and the...