Recent content by emeriska

Homework Statement We have an ordinary LRC circuit with inductance L, capacitance C and resistance R with an oscillating voltage with low frequency (U^e). Using the energy conservation law and Poynting's theorem, find the differential equation: $$L \frac{\partial ^2}{\partial t^2}I + R...

First, sorry if something is not totally clear, I'm translating physics term the best I can! 1. Homework Statement A sphere or radius a of permittivity ε2 is placed in a dielectric ε1. Without the sphere, we would have E = E0. We want to find the solution to this problem when ε2 = 1...

Well I tried something but never got to the energies...anyway, my deadline was tomorrow so I should have the solutions by the weekend. I certainly won't have 100% but if I have anything more than 0 it will be because of you! Thank you very much for your time, much appreciated! You helped me a lot!

H \Psi = \left( \begin{array}& 0 & \sqrt{2} & 0 \\ -\sqrt{2}& 0 & \sqrt{2} \\ 0 & \sqrt{2} & 0 \end{array} \right) \Psi Thanks a lot! I guess I only have to find the stationary states from this matrix? The stationary states would be the line vectors of the matrix is that right? So something...

OH! I see! Rhat's not what I was doing at all. Thanks a lot, I'll see where this leads me

I just edited that last post because you were right for the equation of ##H##

You were right on the equation of ##H## So, I have L_+ |-1\rangle = \sqrt{2} |0\rangle L_+ |0\rangle = \sqrt{2} |1\rangle L_+ |1\rangle = 0 |2\rangle L_- |-1\rangle = 0 |-2\rangle L_- |0\rangle = \sqrt{2} |-1\rangle L_- |1\rangle = \sqrt{2} |0\rangle L_z |-1\rangle = - |-1\rangle L_z...

If my calculus are right I should have ##H = \frac{w_0}{\hbar} L_z(L_++L_-)##

Yes I do know about raising and lowering operators, that I guess I will have to find in terms of $L_u, L_v$ right? But I'm stuck at the very basic. I don't know where to start to write $H$ in a basis. I can't find any example on the web that is even remotely similar to this question. Thanks...

I read this section of my book at least 100 times and I still have no idea how to start this problem. If I start with what you just gave me, how can I compute the values ##\alpha , \beta , \gamma## ? Of maybe you know somewhere else where that is explained?

So I figured ##L_v = \frac{L_z - L_x}{\sqrt{2}}## But I don't see how to convert that into a matrix. We use Griffiths and I feel like my book is not really helping me on that :S

Hi guys, I'm having a hard time with that one from Cohen-Tannoudji, ##F_{VI}## # 6. I'm translating from french so sorry if some sentence are weird or doesn't use the right words. 1. Homework Statement We consider a system of angular momentum l = 1; A basis from it sub-space of states is...

Yes sorry your right! I know it sound really obvious, but I need to prove it...That's what bugging me :S

Oh, and while I'm there, I also need to prove that ##<H> <= E_{1}##, where ##E_{1}## is the fundamental energy. How will I proceed to do that? Do I need to compute ##E_{1}##? Cause if I do, I'll end up with terms in ##\psi_{1}## that I'm not quite sure how to compare with ##\psi_{n}##

I had to read that a couple times but thanks a lot! that really helped!