Does a Photon Bounce? - Learn How Photons Interact with Mirrors

  • Thread starter Thread starter worwhite
  • Start date Start date
  • Tags Tags
    Bounce Photon
Click For Summary
Photons interact with mirrors primarily through coherent interactions with electrons, rather than simple absorption and re-emission. This process is better described by quantum electrodynamics (QED), which calculates probabilities of outcomes rather than detailing the underlying mechanisms. Reflection occurs when a photon interacts with multiple electrons, generating electromagnetic waves that can either reflect back or refract into the material. The concept of a photon "bouncing" off a surface is misleading, as it implies a classical particle behavior that doesn't align with quantum mechanics. Ultimately, the interaction is complex and involves statistical approaches to account for the behavior of countless particles.
  • #31
reilly said:
My apologies, I misread your superimposed state vector.

But for the life of me, I don't understand how you get such a state. If you could explain via the standard QED interaction and Schrodinger Eq. solutions -- even using non-relativistic perturbative solutions -- I would be most grateful.
Thanks,
Reilly Atkinson

http://arxiv.org/abs/0805.2853" mentions some ways to achieve the desired result in a practical way. Take e.g. the entangled state described by Eq. 27 on page 13:

1/sqrt(2) [|a>|a'> + |b>|b'>]

Here |a> and |b> are spatial modes for a photon and the primed states are different spatial modes for another photon. Then you don't have single photon interference, but you do have interference when you measure two photon correlations. All this is quite obvious.

But if you try to interpret the result classically, you get exactly what I wanted to show: You don't get interference even though the light from the spatial modes a' and b' should interfere classically. In case of the state:

1/sqrt(2) [|a'> + |b'>]

Then there would be inteference. In the classical picture, you cannot see the difference between the two cases. So, it is possible to create classical waves that fail to behave as predicted by classical theory.

This is true, in principle, for all classical wave phenomena. You could theoretically create two sources of sound waves such that they should interfere, yet you can make them fail to interfere if the phonons are in certain entangled states (whith other phonons or with some other degrees of freedom)

So, the conclusion must be that you don't necessarily get classical behavior in the classical limit. Or, perhaps one should say that classical wave phenomena like electromagnetic waves are in fact macroscopic quantum phenomena...
 
Last edited by a moderator:
Physics news on Phys.org
  • #32
Details of the calculation: Does it peak in a particular direction due to interference with other possibilities? You don't have a lattice of electrons in a good metal mirror.
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 21 ·
Replies
21
Views
3K
  • · Replies 15 ·
Replies
15
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 16 ·
Replies
16
Views
3K
  • · Replies 29 ·
Replies
29
Views
3K
  • · Replies 6 ·
Replies
6
Views
1K
  • · Replies 38 ·
2
Replies
38
Views
6K