What happens to the physical properties of electrons after diffraction?

Particle Wave duality shows us that waves and particles are the same thing. Therefore electrons can be viewed as both particles and waves. The wave properties of electrons can be seen in the double split experiment where a diffracted electron interacts with itself.

If a single electron was diffracted, what would happen to it's physical properties? How could the mass spread out like the wave? Similarly how would the charge and spin spread out? These properties are usually considered to be contained in particles, yet if a single electron was diffracted, it surely could not become many particles spreading out.

Also, what would happen if something interacted with this 'electron wave' causing part of it to act like a particle again? The wave can't be able to turn back into a particle after spreading out so much, yet it must still be able to act like a particle for certain interactions.

The particle/wave duality at the micro framework where quantum mechanics has to be used does not describe "particles" as billiard balls, nor "waves" as energy/mass waves.

Electrons when displaying "particle" properties are measured at a specific (x,y,z,t) but the values in space are indeterminate according to the Heisenberg Uncertainty Principle. The better we know the location of the electron, the less we know of its velocity. This is not true of macroscopic billiard balls.

Similarly the wave nature observed in the double slit experiment is not a mass/energy wave. I.e. the electron is not spread out in space. The wave nature is displayed as an interference in the probability distribution of the electron's position, "how probable is it to find it at (x,y,z) after the double slit". Therefore a single electron is unaffected by the two slits. What is affected is the probability of finding it on the screen at (x,y).

I think is a misinterpretation of the wave-particle duality.

We always detect electrons as particles, but they have an associated wavefunction $\psi(\vec{x},t)$, which its square gives you the probability of finding the electron at each point.

So in the double slit experiment, the wavefunction (probability wave) diffracts and you see that electrons form a fancy pattern. But that's it, there is no diffraction of mass, spin, etc. because the rest of the electron's properties don't behave like a wave.

• Could you elaborate on "the wavefunction (probability wave) diffracts"? I thought diffraction is a physical phenomenon? How can the (non-physical) probability "wave" be subject to a physical phenomenon like that? Or am I severely misunderstanding this? Commented Aug 1, 2020 at 15:55
• Following along in this context, are phenomena such as interference and diffraction merely alterations to the probability of finding a certain "particle" at a particular "location" in space and time? Commented Aug 1, 2020 at 15:57
• @Dunois I think one could say diffraction is a mathematical phenomenon, you have a function f(x,t) defined in spacetime that satisfies some differential equation. If you impose some restrictions on f, such us being zero at the slit, then f will spread in a fancy way. That's what we call diffraction and the wavefunction satisfies that. Mathematically it's very similar to the electric field and light diffraction. So yes, the probability changes in a fancy way. Commented Aug 1, 2020 at 18:39
• thank you for the clarification! That makes a lot of sense! Commented Aug 2, 2020 at 5:51