Recent content by jaurandt

So then what happens to the rest of the construct if you just pull out $$\left\langle a'\right|X\left|a''\right\rangle $$ What happened to the summation and what becomes of $$\left|a'\right\rangle\left\langle a''\right| $$

Can you please give the same example, but with the ##\sigma_y## operator? What I'm trying to say is that I don't understand how $$\sigma_z = \sum_s \sum_r |s\rangle\langle s|\sigma_z|r\rangle\langle r|$$ Reveals the entries of the matrix...

Look, I am sorry for not being able to post any LaTeX. But I am stuck at a place where I feel I should not be stuck. I can not figure out how to correctly do this. I can't seem to recreate the Pauli matrices with that form using the 3 2-dimensional bases representing x, y, and z spin up/down...

I do not know what I'm doing wrong but I'm working on the problem of finding the normalization constants for the energy eigenstate equation for a 1D plane wave that is traveling from the left into a potential barrier where E < V at the barrier. This is from Allan Adams' Lecture 12 of his 2013...

Thank you!

Sorry, I will do so from now on. But what's most important to me is the problem for the sake of my sanity...

Attached is a personal problem that I spent last night working on for about 2 hours and something is going wrong, I just can not figure it out what. The answer by the big X is what I wound up with but it's obviously not correct. Could someone please guide me through solving this? The starting...

Fair enough.

As far as I know, a real number is it's own complex conjugate, just like 0.

To specify, yes a 12 by 12 matrix where elementij = i*j where elementsii = i*i (1, 4, 9, 16, ... , 144) It is a Hermitian matrix and I was in fact wondering if it could apply to some observable of a system.

I was drawing out the multiplication table in "matrix" form (a 12 by 12 matrix) for a friend trying to pass the GED (yes, sad, I know) and noticed for the first time that the entries on the diagonal are real, i.e. the squares (1, 4, 9, 16, ...), and the off diagonal elements are real and complex...

Yeah, that's the next lecture series I'm moving onto after Allen Adams'. He talks and moves so fast... I never could've gone to MIT...

I own the Susskind book, which I have mostly read. I would prefer it to be an undergraduate level, but anything that can teach QM in a clear way (without glossing over things) will do.

I meant for the title of this to say "Good Books on Quantum Mechanics", I'm no where close to QFT yet. Can a mod change it for me?

I'm trying to do this by myself. I went through Dr. Susskind's 10 lecture series (the older one, not as much aligned with his book "Quantum Mechanics", which I own) taking notes, and am almost half way through with MIT Open Courseware's lectures in 8.04 (QM I) from 2013, again taking rigorous...