3
$\begingroup$

This question already has an answer here:

Are photons electromagnetic waves, quantum waves, or both?

If I subdivide an electromagnetic field into smaller electromagnetic fields, should I eventually find an electromagnetic wave of a photon?

How can individual quantum waves combine to form the macroscopic observable of an electromagnetic field?

$\endgroup$

marked as duplicate by John Rennie, DavePhD, Kyle Kanos, Brandon Enright, Kyle Oman May 20 '14 at 19:33

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • $\begingroup$ possible duplicate of Is the wave-particle duality a real duality? $\endgroup$ – John Rennie May 20 '14 at 13:54
  • 1
    $\begingroup$ A photon is a single excitation of an electromagnetic mode. So you can have photons of standing waves (see cavity QED), photons of free propagating modes, etc. $\endgroup$ – webb May 20 '14 at 14:42
4
$\begingroup$

Are photons electromagnetic waves, quantum waves, or both?

A great ensemble of photons build up the electromagnetic wave.

If I subdivide an electromagnetic field into smaller electromagnetic fields, should I eventually find an electromagnetic wave of a photon?

This experiment has been done with lasers bringing down to individual photon strength in this double slit experiment:

photon double slit

The movie shows the diffraction of individual photon from a double slit recorded by a single photon imaging camera (image intensifier + CCD camera). The single particle events pile up to yield the familiar smooth diffraction pattern of light waves as more and more frames are superposed (Recording by A. Weis, University of Fribourg).

You ask:

How can individual quantum waves combine to form the macroscopic observable of an electromagnetic field?

It needs some strong math background, but handwaving:

Both the classical electromagnetic wave and the quantum photon rely on solutions of maxwell's equations. The individual photons carry information about the frequency ( E=h*nu) and the spin and electromagnetic potential in the equation, since the quantum mechanical wavefunction of the photon ( which gives the probability distribution of the photon) and the classical wave depend on the same equations. There is a coherent synergy and the zillions of photons add up to give the classical wave.

$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.