All Questions
5
questions with bounties
11
votes
3
answers
358
views
+50
A rigorous derivation of Hund's rules
I was really looking forward to the atomic physics portion of my quantum mechanics class and was pretty disappointed with Griffith's hand-wavey qualitative description that was scarcely above the ...
3
votes
1
answer
59
views
+50
How does the Hong-Ou-Mandel (HOM) effect conserve photon momentum?
HOM is a two-photon interference effect where temporally overlapped identical photons coming perpendicular to a beam splitter must leave it in the same direction.
How is momentum conserved in this ...
2
votes
8
answers
323
views
+200
Why does a higher frequency mechanical wave have more energy?
(that question may sound like my last question What makes a higher frequency sound wave more energetic? but I wouldn't consider it a duplicate, the focus is very different.)
Comparing two mechanical ...
3
votes
1
answer
631
views
+100
Landau&Lifshitz's derivation of the law of entropy increase - clarification
In Landau&Lifshitz V: Statistical Physics the following derivation of the law of increase of entropy is given. I need help understanding several crucial steps; I'll briefly summarize the notations ...
5
votes
1
answer
127
views
+200
A limit of a particular Quantum Fidelity
I have the following problem.
Let $\mathbf{\hat{\rho}}(t)$ and $\mathbf{\hat{\sigma}}(t)$ be two trace class positive operators acting on a Hilbert space of infinite dimension for all $t > 0$. More ...