Undergrad How does an electron interact in QFT?

[Philipsmett]

How does the electrons interact in QFT? if they are not localized? For example, when one electron repels another or does an atom repel another atom? How do electrons find each other for interaction?

 

[A. Neumaier]

They are excitations of the electron field which interacts locally. Like water wavelets, but quantum and hence more complicated...

 

[Orodruin]

I would just add that the interaction term of the electron field current $\bar e \gamma^\mu e$ is with the photon field. This is also true classically. Even classically charged particles do not interact by being in the same position, they interact through their interaction with the classical electromagnetic field.

 

[Philipsmett]

I would just add that the interaction term of the electron field current $\bar e \gamma^\mu e$ is with the photon field. This is also true classically. Even classically charged particles do not interact by being in the same position, they interact through their interaction with the classical electromagnetic field.

How do two electrons interact if they are not localized?

 

[Orodruin]

How do two electrons interact if they are not localized?

Classically, electrons are localised, but they do not need to be in the same position to interact with each other. The reason for this is that they interact via their interactions with the electromagnetic field. Compare with the force between two magnets which is there even if they are not in the same place. You need to understand this in order to have any cance of understanding the quantum theory.

 

[Philipsmett]

Classically, electrons are localised, but they do not need to be in the same position to interact with each other. The reason for this is that they interact via their interactions with the electromagnetic field. Compare with the force between two magnets which is there even if they are not in the same place. You need to understand this in order to have any cance of understanding the quantum theory.

That is, electron create around themselves disturbances in the electromagnetic field?

 

[bhobba]

That is, electron create around themselves disturbances in the electromagnetic field?

Loosely you could express it that way.

The following may help:
http://www.physics.usu.edu/torre/3700_Spring_2015/What_is_a_photon.pdf

As explained above the coupling mentioned previously is responsible for real effects such as spontaneous emission that can not be explained any other way.

How the force between charged particles arises in QFT has been discussed in other threads:
https://www.physicsforums.com/threads/electron-repulsion-in-qft.964567/#post-6121372

Thanks
Bill