I The physical components in the electron double slit experiment

[jacobbry]

TL;DR Summary

I would like to know all the physical components involved in the electron double slit experiment. Including the observer, detection and effects that each of these have on the electron.

I understand the results of the electron double slit experiment and wish to find out why it is the case. I need to start with a more full understanding of the physical interactions taking place:
What is the “observer”, I understand that high energy light is used as an observer sometimes but what are others and exactly how do they all effect the electron.

What is the detection screen made or and what specifically does it detect, I know that the mass of an electron is far to small to be detected so the obvious answer is that the detection screen detects the charge or the electromagnetic field/ waves of the electron.

At what stage in the experiment is the electron observed and how does the point it is observed alter the outcome of the experiment.

If an photoelectron collides with a high energy photon what are the changes to the electron.
I believe the answer to these questions could really help with my understanding of the physical components at play so I would appreciate anyone taking the time to answer my questions.

 

[phinds]

I know that the mass of an electron is far to small to be detected

It is unfortunate that you "know" that, since it is wrong. How do you think cathode ray TV tubes work? What is it that you think causes the pattern on the detector screen in the double slit experiment, if it is not the electrons being "detected" ?

 

[jacobbry]

I ment that I believed that I could ignore the detection of the mass of the electron as that is a property of particles and so can’t be what is used to detect electrons as a wave when they are not being “observed”. I didn’t think it was relevant to my underlying questions but if is is then please tell me why.

 

[Ibix]

The detection screen simply absorbs kinetic energy and re-emits it in a way we can see or otherwise record. The low-tech solution is just a phosphor paint that glows when hit by electrons, the same as old cathode ray tube TVs.

My understanding is that modern quantum physics doesn't really bother about "observers", but I'm not an expert. I'll ask for this thread to be moved to the quantum forum, since I think that's your main interest.

 

[Lord Jestocost]

TL;DR Summary: I would like to know all the physical components involved in the electron double slit experiment. Including the observer, detection and effects that each of these have on the electron.

I understand the results of the electron double slit experiment and wish to find out why it is the case. I need to start with a more full understanding of the physical interactions taking place:
What is the “observer”, I understand that high energy light is used as an observer sometimes but what are others and exactly how do they all effect the electron.
What is the detection screen made or and what specifically does it detect, I know that the mass of an electron is far to small to be detected so the obvious answer is that the detection screen detects the charge or the electromagnetic field/ waves of the electron.
At what stage in the experiment is the electron observed and how does the point it is observed alter the outcome of the experiment.
If an photoelectron collides with a high energy photon what are the changes to the electron.
I believe the answer to these questions could really help with my understanding of the physical components at play so I would appreciate anyone taking the time to answer my questions.

Maybe, this paper might be of help:

A. Tonomura, J. Endo, T. Matsuda, T. Kawasaki and H. Ezawa, “Demonstration of single-electron buildup of an interference pattern”, Am. J. Phys. 57 (1989) 117-120.

 

[PeterDonis]

I ment that I believed that I could ignore the detection of the mass of the electron as that is a property of particles and so can’t be what is used to detect electrons as a wave when they are not being “observed”.

This is all nonsense. Where are you getting your understanding of QM from?

 

[Nugatory]

I meant that I believed that I could ignore the detection of the mass of the electron as that is a property of particles and so can’t be what is used to detect electrons as a wave when they are not being “observed”. I didn’t think it was relevant to my underlying questions but if is is then please tell me why.

The idea of wave-particle duality, that the electron acts like a wave until it is observed and then it acts like a particle is not part of the modern understanding of quantum mechanics and has not been for almost a century now.

There is no substitute for a real textbook that uses some amount of math to present the theory properly, but I can offer up a handwaving answer: the electron is neither a particle nor a wave. It is something whose properties are described by a quantum mechanical wave function (and has no classical analogue). One of these properties is the probability of it interacting with the screen at any given location. So we send a bunch of electrons through our experimental apparatus; we observe from the pattern of dots which parts of tthe screen have a high probability of interacting with an electron; we compare this with the probabilities we calculated from the wave function and we find that they match.

For a more satisfying explanation, I highly recommend the paper that @Lord Jestocost references above (although is may be difficult to find a copy that is not behind a paywall... Perhaps someone knows of a more recent experiment that might be found on arXiv?)

 

[DrChinese]

n and we find that they match.

For a more satisfying explanation, I highly recommend the paper that @Lord Jestocost references above (although is may be difficult to find a copy that is not behind a paywall... Perhaps someone knows of a more recent experiment that might be found on arXiv?)

A. Tonomura, J. Endo, T. Matsuda, T. Kawasaki and H. Ezawa, “Demonstration of single-electron buildup of an interference pattern”, Am. J. Phys. 57 (1989) 117-120.
https://www.u-cursos.cl/ingenieria/2007/2/FI34A/1/material_docente/detalle?id=139739

Also, I recommend a paper using photons - which I think are better to understand the basic concepts:

Young's double-slit experiment with single photons and quantum eraser
https://www.researchgate.net/public...riment_with_single_photons_and_quantum_eraser

This paper deals with the "observer" effect (hint: no observer required).