There are a lot of questions on this site about photons and wavepackets.
This one lists a lot of them as reference. None of them in detail specifically answers my question.
I have read this:
A wave.packet enters the beam splitter and breaks into two smaller wave.packets. The incident particle, shown as a dot in picture, emerges along path a accompanied by a wave packet. The wave packet in path b is empty.
I am not asking about the photon traveling as a wave, or a particle, or why the photon is delocalized when traveling and why it is taking all possible paths. I am not asking what happens when a photon hits a beam splitter.
I am asking if it is really possible what the paper suggests, that there can exist a wavepacket, without a photon, that is, where the photon number is 0.
In physics, a wave packet (or wave train) is a short "burst" or "envelope" of localized wave action that travels as a unit.
The best definition of a wavepacket I found on this site is saying that a wavepacket is basically a localized excitation of the EM field. This is a contradiction, because the photon itself is usually defined as the excitation of the EM field. How could there be a wavepacket (a localized excitation), without a photon (excitation of the EM field)?
- What is a wavepacket without a photon?