Delayed choice quantum eraser question

In summary, the article says that you have to separate the marks you don't have which-path information for in order to get an interference pattern.
  • #1
cornernote
6
0
I have a question about the delayed choice quantum eraser with the double split experiment. Forgive me if this is a silly question.I have seen the following:

TEST 1
1. shoot the particles & measure the result
2. erase the result
3. check the wall (whatever you shot the particle at)
= wall shows inteference pattern

TEST2
1. shoot the particles & measure the result
2. check the result
3. check the wall
= wall shows non inteference patternI would like to know the following result:

TEST 1
1. shoot the particles & measure the result
2. check the wall
3. erase the result
4. check the wall again

TEST 2
1. shoot the particles & measure the result
2. check the wall
3. check the result
4. check the wall again

Could you possibly get an inteference pattern at step 2 and then a non inteference pattern at step 4 or vise-versa?
 
Physics news on Phys.org
  • #2
I don't know if bumps are allowed here, but I would really like to know the answer to this question.
 
  • #3
Well I personally don't get your question. You need to frame it more precisely & I suspect you misunderstand parts of it. The only thing that changes is your interpretation of "what actually happened."

I just dug up a http://rapidshare.de/files/33406957/875.pdf.html" pdf article. Hope it helps.
 
Last edited by a moderator:
  • #4
As far as I understand these experiments, the wall never shows an interference pattern. If you refer back to published results, you should notice that the interference fringes are only in the coincidence data.
 
  • #5
Somethin i figure was weird about that experiment tho. U know which path the particle takes 50% of the time and don't the other 50%. Every time a particle hits the "wall" it makes a mark. U colour in all the marks that u have no which-path info for and they form an interference pattern. If u rubbed them out instead, wouldn't you also get an interference pattern? (Non inteference pattern - inteference pattern = inteference pattern) If so, does this mean the particles that you did get which-path info for still interfere?
 
  • #6
Don't think so wiz. Possibilities:
1) slit A: gaussian
2) slit B: gaussian
3) slit A + slit B: fringes
4) slit A - slit B: antifringes
 
  • #7
Awh! If i understand u right, that makes so much more sense. Actually solves a different question that was in my head too! Brian Green didnt mention u had to separate the marks u don't hav which path info for in2 3 & 4 to get the patterns.

Are 3 & 4 the 2 different "no-which-path" detectors? Or hav i completely misinterpreted ur post
 
  • #8
Yes, that seems to be the experimental result, maybe someone else could explain the theory behind those two different versions of "no-which-path"?
 

1. What is the delayed choice quantum eraser experiment?

The delayed choice quantum eraser experiment is a thought experiment that explores the concept of wave-particle duality in quantum mechanics. It involves a setup where a photon is split into two entangled particles, one of which passes through a double-slit apparatus and the other goes through a detector. The interesting part is that the experimenter can choose to either measure which slit the particle went through or not, even after the particle has already passed through the double slit.

2. How does the delayed choice quantum eraser experiment work?

In the delayed choice quantum eraser experiment, a photon is directed towards a beam splitter which splits it into two entangled particles, known as signal and idler. The signal particle goes through a double-slit apparatus while the idler goes to a detector. The experimenter can choose to either measure the path of the signal particle or not. If the path is measured, the interference pattern is lost. But if the path is not measured, the interference pattern is present. This shows that the act of observing or not observing can affect the behavior of the particles.

3. What is the significance of the delayed choice quantum eraser experiment?

The delayed choice quantum eraser experiment challenges our traditional understanding of causality and the concept of time in the quantum world. It suggests that the present can affect the past and that the act of observation can change the outcome of an event that has already occurred. This has implications for our understanding of reality and the role of consciousness in the quantum world.

4. Are there any real-life applications of the delayed choice quantum eraser experiment?

While the delayed choice quantum eraser experiment may seem like a purely theoretical concept, it has practical applications in fields such as quantum cryptography and quantum computing. It also helps scientists better understand the fundamental principles of quantum mechanics and its implications for our understanding of the universe.

5. Is the delayed choice quantum eraser experiment accepted by all scientists?

The delayed choice quantum eraser experiment is a highly debated topic in the scientific community. While some scientists accept its implications and use it to further their understanding of quantum mechanics, others are skeptical and propose alternative explanations. Further research and experimentation are needed to fully understand the implications of the delayed choice quantum eraser experiment.

Similar threads

Replies
8
Views
844
Replies
4
Views
744
Replies
3
Views
1K
Replies
19
Views
866
Replies
18
Views
1K
Replies
2
Views
595
Replies
1
Views
583
Replies
23
Views
2K
  • Quantum Physics
Replies
1
Views
728
Replies
15
Views
1K
Back
Top