Particle and three slits + one detector experiment

[Mazuz]

What would happen if the slit experiment is done with three slits and at only one slit some sort of particle detecting or particle tagging device is placed and at the remaining slits no means of particle detecting is introduced.

I know the results of two slits with and without two detectors. But in this other scenario I imagine that perhaps a third of the particles shot will read on the detector and will land without an interference pattern, and the others will go undetected and will land with some kind of interference pattern between the other two slits. But I’m wondering if the presents of a single detector will foul the whole thing up somehow ending with no interference pattern result at all. Answering this question will help my thinking on the slit issue a lot.

 

[nightlight]

Originally posted by Mazuz
But I’m wondering if the presents of a single detector will foul the whole thing up somehow ending with no interference pattern result at all. Answering this question will help my thinking on the slit issue a lot.

The experiments with slits, edges, half-silvered mirrors,... always behave exactly as the EM waves would indicate. There is http://wildcard.ph.utexas.edu/~sudarshan/pub/1963_002.pdf with more details). It only appears mysterious if you insist on imagining photons as particles. If you place 2 detectors, one right behind each slit in a double slit experiment, you will find that detector counts are generated on each slit independently from the counts on the other slit i.e. the wave packet leaving slit A and entering detector A will trigger or not trigger detector A independently on what the other wave packet did on detector B -- there is no collapse of EM wave packet A when packet B triggers detector B (explained as "photon bunching" in particle + wave-collapse imagery).

 

[R0man]

In this scenario, where one slit has a particle detecting device and the others do not, the results of the experiment would depend on the type of particle being used and the sensitivity of the detector.

If the particle is a classical particle, such as a macroscopic object, then the presence of the detector at one slit would not affect the interference pattern at the other two slits. This is because classical particles do not exhibit wave-like behavior and do not interfere with themselves. Therefore, the particles passing through the other two slits would still create an interference pattern on the detector screen.

However, if the particle being used is a quantum particle, such as an electron or photon, then the presence of the detector at one slit would indeed affect the interference pattern at the other two slits. This is because quantum particles exhibit wave-like behavior and can interfere with themselves. The detector at one slit would collapse the wave function of the particle, causing it to behave like a classical particle and not interfere with itself. This would result in no interference pattern on the detector screen.

Moreover, the presence of the detector at one slit would also introduce a measurement problem. The act of measuring the particle would disturb its state and affect its behavior, making it impossible to accurately predict its path through the other two slits. This would further contribute to the lack of interference pattern on the detector screen.

In summary, the presence of a particle detecting device at one slit in a three-slit experiment would affect the behavior of quantum particles and disrupt the interference pattern on the detector screen. This highlights the delicate nature of quantum systems and the impact of observation on their behavior.