Linked Questions

244 votes
22 answers
43k views

What exactly is a photon?

Consider the question, "What is a photon?". The answers say, "an elementary particle" and not much else. They don't actually answer the question. Moreover, the question is flagged as a duplicate of, "...
John Duffield's user avatar
23 votes
1 answer
5k views

Are photons actually particles at all?

I just read this answer to "What exactly is a Photon?" which has me a bit confused. It seems to be arguing that "photon" is just a catch-all term for any sort of interaction with ...
Mikayla Eckel Cifrese's user avatar
12 votes
2 answers
2k views

Why doesn't there exist a wave function for a photon whereas it exists for an electron?

A photon is an excitation or a particle created in the electromagnetic field whereas an electron is an excitation or a particle created in the "electron" field, according to second-quantization. ...
Saurabh Shringarpure's user avatar
4 votes
1 answer
2k views

Does a photon have a wave function or not?

I have read this question: Why doesn't there exist a wave function for a photon whereas it exists for an electron? where annav says: Here is the [wavefunction of the photon,][1] which is a ...
Árpád Szendrei's user avatar
3 votes
2 answers
2k views

Can we define a wave function of photon like a wave function of an electron? [duplicate]

By definition, the wave function can be obtained by acting the position eigenstate to a state of the system, e.g., $\langle x\vert \psi \rangle$. For the wave function of an electron travelling in one-...
Veteran's user avatar
  • 655
2 votes
1 answer
373 views

Physical interpretation of photon propagator

Physically, propagator represents the probability amplitude of a particle to travel from one point to another. But the photon propagator $$D_{\mu\nu}(x,y) = \langle 0 | \mathcal{T}[A_\mu(x) A_\nu(y)] ...
SCh's user avatar
  • 778
4 votes
1 answer
280 views

What does it mean to measure a photon?

In a lab at the university where I'm studying, there's a detector of gamma rays. We bring a radioactive caesium source near the detector, and the detector clicks now and then. The closer the source is ...
roymend's user avatar
  • 842
0 votes
2 answers
222 views

What happen to the electromagnetic waves when a photon's "wave function" collapses?

We interpret the electron's wave function as a probabilistic wave function. During a measurement, it has the probability to collapse to any of the eigenstates of the measurement operator based on the ...
JNL's user avatar
  • 393
1 vote
1 answer
179 views

Is photon's direction entangled?

Consider a free electron, with photon, that runs to electron under some angle(as everybody says). Compton scattering is happening, and electron instantly reemits photon in different angle. First, ...
user avatar
1 vote
0 answers
147 views

What is the physics corresponding to the "wave function of a single photon"?

Some of you may have seen my post yesterday which asked essentially the same question as I'm going to ask here and has since been deleted, for which I apologize. I noticed some egregious errors in my ...
Cody Payne's user avatar
2 votes
0 answers
111 views

Without strict photon position observable (spatial probability density), how is the double slit experiment possible?

I have read this question: EM wave function & photon wavefunction Wave function of a photon? where Arnold Neumaier says: photons do not have a spatial probability density He specifically ...
Árpád Szendrei's user avatar
1 vote
1 answer
58 views

How do electromagnetic wave and photons wave function correspond? [duplicate]

Regarding two-slit experiment against photons makes me conclude, that both frequency and phase of electormagnetic wave and photon wavefunction coincide in space and time. Am I right? If I am right and ...
Dims's user avatar
  • 1,742