All Questions
15
questions
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75
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Problem with Bohr Frequency in Quantized Radiation - Matter interaction
Consider an Hydrogenic Atom (no relativistic corrections and no reduced-mass effects) in a Quantized Electromagnetic Pulse given by the wave-packet:
$$
\underline{\hat{A}}(\underline{\hat{r}}, t) = \...
- 402
0
votes
2
answers
161
views
Electromagnetic field affect on hydrogen atom energy levels
If hydrogen atom is in the ground energy state it must be hitted by photon with energy higher than electron proton energy binding which is 13,6 eV according quantum mechanics. Proton have positive ...
- 119
1
vote
1
answer
71
views
What happens when a photon interacts with a free electron?
When an electromagnetic wave interacts with a free electron the electron starts to oscillate in the direction perpendicular to the propagation of the wave meanwhile when a photon interacts with a free ...
- 866
1
vote
2
answers
128
views
Second Harmonic Generation in metals
Assuming a metal driven by a femtosecond laser pulse could generate second harmonics, are these harmonics radiative?
In other words, do they reach the far-field?
- 185
0
votes
0
answers
36
views
Role of "cavities" in quantum light absorption
I am currently studying the basics of Quantum Electrodynamics, and I have learned from this that photons are the quanta of excitation for given field modes. In other words, when a photon is absorbed, ...
- 366
2
votes
2
answers
656
views
What actually causes the electromagnetic field to be quantized?
My understanding is that quantization in QM is because the wavefunctions are analogous to classical standing waves, where the boundary conditions determine the specific quantization. That's how it ...
- 2,327
2
votes
1
answer
101
views
What is the exact form of the interaction Hamiltonian mentioned in Schwartz's book?
In the book "Quantum Field Theory and the Standard Model" by Schwartz, in eq. (1.24) of chapter 1, he mentions that the interaction Hamiltonian for a particle going from state $i$ to $f$ is ...
- 392
2
votes
4
answers
125
views
Is it just a co-incidence that the interference pattern of light can both be explained using a classical wave and using a probability function?
Approach 1-Light can be thought of as a vector electric field wave. To explain the interference pattern, one can just add the electric fields like vectors and calculate the intensities.
Approach 2- On ...
- 949
1
vote
1
answer
473
views
Why is Thomson scattering the low energy limit of Compton scattering?
I understand why the classical Thomson scattering computation should not match the QED one, since a classical field is composed of many photons, while Compton scattering involves a single photon. This ...
- 801
0
votes
1
answer
70
views
Can a photons wavelength be independent of its associated temporal wavefunction?
Typically a traveling photon is described as being in a superposition of frequency modes $\hat{E} = \int g(\omega) a^\dagger_\omega d\omega + h.c. $ where often the $g(\omega)$ is some kind of pulse. ...
- 2,193
3
votes
1
answer
842
views
The origin of quantization
I will present a question which already is buzzing in my head for quite a time. Actually quantum physics developed as a interplay of empirical results and theoretical developments where it is ...
- 9,778
1
vote
0
answers
70
views
How does Einstein's oscillatory & quantum structure of radiation from 1909 relate to modern physics
In his 1909 lecture The Development of Our Views on the Composition and Essence of Radiation Einstein discusses two structures of "radiation":
As far as I know, no mathematical theory has been ...
- 171
0
votes
1
answer
232
views
Stimulated emission direction
Place a sub-micron clump of crystal violet molecules in front of a multipixel detector. Raise the molecules to an electronically excited state with a beam of 590 nm light, illuminating from the side ...
- 3,433
5
votes
2
answers
1k
views
If photons don't interact directly, how can electromagnetic waves interfere?
If photons don't interact directly, how can electromagnetic waves interfere? I know that photons can scatter via higher order mechanisms, but not directly. Does those mechanisms explain the classical ...
- 2,897
10
votes
3
answers
8k
views
Properties of the photon: Electric and Magnetic field components
Consider an electromagnetic wave of frequency $\nu$ interacting with a stationary charge placed at point $x$. My question concerns the consistency of two equally valid quantum-mechanical descriptions ...
- 7,398