0
votes
1answer
498 views

Photons and phonons

A few months ago I asked about phonons. I got some very good answers but I still have difficulty getting an intuition for phonons, while somehow photons, which in many ways are similar and which I ...
20
votes
2answers
949 views

What is a phonon?

I am trying to understand intuitively what a phonon is, but for the moment I find it quite difficult (having a limited background in quantum mechanics, an undergraduate course in non-relativistic QM). ...
9
votes
3answers
599 views

Phonon carries zero spin. Why?

photons and phonons both have polarization, we attribute spin 1 for photons but spin 0 for phonons. Why?
2
votes
1answer
66 views

What is the first paper to report observations of polaritons?

I am seeking references to the first articles regarding the observation of polaritons.
2
votes
0answers
104 views

Phonon-polariton literature resources? [closed]

What is a good resource for studying phonon-polaritons?
7
votes
2answers
1k views

How to get an imaginary self energy?

The Lehman representation of the frequency-dependent single particle Green's function is $$G(k,\omega) = \sum_n \frac{|c_k|^2}{\omega - E_n + i\eta}$$ where $n$ enumerates all the eigenstates of the ...