An electron-electron interaction that is mediated by a photon is a process in which two electrons interact with each other through the exchange of a photon. The process is common and is responsible for many of the properties of matter.
- Imagine electrons as tiny magnets with an electric field surrounding them. This electric field affects the space around them.
- When two electrons are close, their electric fields push against each other because they have the same charge (like poles of magnets repel).
- According to the theory of quantum electrodynamics (QED), electrons can’t directly interact with each other. Instead, they exchange energy in the form of a photon, the carrier of the electromagnetic force.
- One electron emits a photon due to a fluctuation in its electric field. This photon carries some energy and momentum.
- The other electron, influenced by the changing electric field of the first electron (carried by the photon), absorbs the photon. This changes the second electron’s energy and momentum.
- So, even though the electrons never directly touch, the exchanged photon acts as a messenger, causing a repulsive force due to the way their electric fields interact.