Recent content by phy127

Thanks for your reply Dr. Transport I know, AlAs is an indirect material. But the well is anyway GaAs. So I just need the AlAs bandgap at the zone center for calculating the confinement energy in the GaAs well. (Am I right in doing this?) Yes, I completely taken into account the 2D nature of...

I have tried solving for the exciton energy in GaAs/AlAs QWs but my calculated results do not agree with published experimental results. My model in the calculation is just a single GaAs well with AlAs barriers. Using the material parameters of both materials, and the well width, I calculated...

I am solving an eigenvalue problem -- Hamiltonian problem in Quantum Mechanics. The matrix is 8x8 with off-diagonal terms, but some are zero. It is well known that the eigenvalues of a Hermitian matrix anti-cross as it nears each other. This is very easy see if the matrix have an independent...

I'm reading the pdf file you directed. It's too hard for me. I don't have very good mathematical foundations. Maybe this needs a lot of time. After some time, I will post a reply if things are getting better, or worse. About Mathematica, I'll stick with Matlab as I need to do this in Matlab or...

Sorry if I misunderstood you kai. I'm not really good with linear algebra and I don't know exactly how can I do the method you are presenting. I will give it a try if you will help me lay it all. Of course that will consume your time. :))

Thanks kai_sikorski Your first reply is elegant! But unfortunately, my system is nonlinear. I have been searching around too and found that your second reply is the commonly used method. On the other hand, I'm interested in the MATLAB function you presented. As for my problem, the number of...

I have a system of coupled ODEs which tells the propagation of power Pi in an optic fiber. \frac{\partial P_i }{\partial z} = \left (N\sigma - 1 \right ) P_i where N = \frac{\sum_i \alpha_i P_i}{\sum_i \beta_i P_i + 1} If the signals are copropagating, there is no problem since...

Thank you very much Cthugha.. I think I'm ready to read again.. Just cleared some doubts. I hope you will still be there if I have some queries again. Thanks very much again. :)

Thanks Cthugha. You explain just so well. Yes, my study is on microcavities with embedded with quantum wells, the very microcavity used in polariton studies today. Again, you're right, I am introducing different strains to manipulate the valence band energies. The strain may be introduced...

Thanks for the quick reply. This means there are 8 distinct exciton states? Which can be identified by their spin projection. 4 bright excitons (S=1) 2 dark excitons (S=2) Are the S=0 states bright? I can't think of I way how it can couple to photon. I'm studying exciton-photon coupling in...

I am actually curious about the spin of excitons. Since an exciton is a bount electron-hole pair, its spin is the sum of the spin of electron and hole, AM I RIGHT? If I use the usual addition of angular momentum in quantum mechanics, I get spin 2,1, and 0. I used the fact that electrons...

Hi, I am also interested in polaritons, but on microcavity exciton-polaritons only. I believe you are asking about phonon-polaritons. Based on my understanding, the dispersion relation for polaritons, like any other materials, depend primarily on the dielectric function. \frac{c^2 k^2}{\omega...