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I am familiar with the Faraday Effect, but I am not talking about that. Even though photons do not have any electric charge or magnetic field, they are still composed of oscillating electric and magnetic waves. I do not get why these electric and magnetic components do not align with an electric/magnetic field, and as the result, cause the photon's direction to align with the field. For an analogy of what I'm trying to say, imagine the photon's direction as an electromagnetic arrow that aligns itself with the (imaginary) lines of an electric/magnetic field.

I have looked at this question, and its first answer says that in order for a photon to be able to align, it must first loose information on its original polarization through dissipation (e.g., absorption). I do not understand how the polarization of light has anything to do with this, as direction of a photon and the polarization of a photon are 2 different things. Another answer for that question also talked about photons interacting with electric/magnetic fields through Delbruck scattering by the photon splitting into virtual electron-positron pairs. However, such interactions are very improbable and require high energy photons (e.g., gamma rays).

Forgive me if my question isn't worded correctly or my understanding is screwed up; I'm a bit of an amateur in the field of quantum mechanics. Any answers would be much appreciated.

Cyber Blade
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    Neglecting tiny QED effects, electromagnetic fields/waves don’t interact; they just superpose (i.e., combine additively). Two flashlight beams pass right through each other. This is because Maxwell’s equations are linear. – Ghoster Sep 04 '23 at 04:18
  • The direction of the E (and B) fields of a photon is the polarisation of the photon. The photon is neutral, in particular, not charged, and thus is not being affected by the ability of E and B fields to align charges along them, oscillations or not. Your question is a bundle of misconceptions. Welcome to Phys.SE – naturallyInconsistent Sep 04 '23 at 04:27
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    The word "photon" is not to be confused with classical electromagnetic light. Photons do build up em light but are not light, as bricks are not a building. look at the mainstream physics definition of a photon . Photons are zero mass point particles traveling with velocity c and spin +/-1. May be my answer here will help https://physics.stackexchange.com/questions/273032/what-exactly-is-a-photon/273180#273180 – anna v Sep 04 '23 at 04:29
  • @naturallyInconsistent I thought that the polarization of a photon refers to the plane of oscillation of the electric and magnetic waves, not the overall direction of propagation? please look at the following image link: https://www.baumer.com/medias/sys_master/images-content/images-content/h98/hae/8940792119326/Grafik-Polarisation-2-EN.gif – Cyber Blade Sep 05 '23 at 23:41
  • @annav I looked over at the link you provided. Thank you very much for correcting me. – Cyber Blade Sep 05 '23 at 23:49
  • @CyberBlade The direction of the E and B fields of a photon = polarisation, will also determine its direction of propagation. Those are all different things. Again, your question is a lot of misconceptions tangled together. The image is correct but does not say what you think it says. – naturallyInconsistent Sep 06 '23 at 04:07
  • @naturallyInconsistent sorry if I am asking too many questions here, but are referring to the direction of a photon being able to change through polarization if the electric and magnetic wave planes of a photon change from one axis to another, and therefore, this polarization will consequently also change the direction of the photon? – Cyber Blade Sep 06 '23 at 04:14
  • @CyberBlade Let us consider a photon moving in the +z direction with the E field polarised in the x direction. If this photon passes through a region with a fixed and moderately large E field that is fixed in the +y direction, the result is a photon that continues to move in the +z direction with E field polarised in the x direction as it originally was. There will not be a change. You need charges to feel that the E field has changed from purely in the +y direction, to having a little bit in the x directions. You need to be much clearer in what it is you want us to consider. – naturallyInconsistent Sep 06 '23 at 04:19
  • @naturallyInconsistent so then could you explain how the polarization of a photon affects its direction of propagation? is this like some poynting vector right hand rule? – Cyber Blade Sep 06 '23 at 14:44
  • Yes it is to do with that. But no, I think you will be better served by a standard textbook introduction to the topic. – naturallyInconsistent Sep 06 '23 at 15:02
  • Thing is, I do not get how polarization is relevant to the topic if we are talking about photons aligning with an electric or magnetic field. – Cyber Blade Sep 07 '23 at 23:14

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Both an electric and magnetic field do indeed cause a rotation of the electro-magnetic alignment of photons. The magnetic influence was already described by Faraday in 1845. The electric influence is described by Kerr in 1875. In nature, birefringence is based on a favorable alignment of atoms in the crystal, which causes an electro-magnetic splitting of a light beam into two beams polarized at the output of the crystal.

No matter how EM radiation is treated mathematically, it is a fact that its generation is always due to the emission of excited states of atoms and thus consists of photons. Each photon has its oscillating magnetic and electric field components. As is known, there are the single photon experiments for the double slit experiment. And just as a stream of photons behind the slit is polarized, so are the single photons in the single photon experiment.

HolgerFiedler
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