Quantum Eraser: do entangled photons arrive at different moments?

In summary, the Delayed Choice Quantum Eraser experiment involves paired photons reaching detectors A, B, C, or D after their entangled pair has reached the interference screen. It is questioned whether the time interval between the photon reaching the screen and its entangled pair reaching a detector can be measured. The longest interval ever recorded between these events is also of interest. The paper describing this experiment can be found at the link provided, which includes information about the detector D0 and coincidence counter circuitry. These components were left out of the image posted, possibly due to a lack of understanding or an attempt to simplify the experiment.
  • #1
Leonardo Muzzi
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TL;DR Summary
In a Delayed Choice Quantum Eraser experiment, do we know if paired photons actually arrive at different moments in time?
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Considering a Delayed Choice Quantum Eraser experiment such as the one in the picture above:

It is said that paired photons arriving at the detectors A,B,C,or D, reach the detectors after the entangled pair has reached the interference screen.

Are we actually able to measure the time interval between the photon reaching the screen and its entangled pair reaching one of the detectors? How is this measurement made?

If yes, what is the longest interval ever made between these two events?
 
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  • #2
The paper describing this experiment is here: https://arxiv.org/abs/quant-ph/9903047

Note the detector D0 and the coincidence counter circuitry. Whoever drew the image you posted left these out either because they didn't understand their importance or in a misguided attempt to simplify the experiment for non-specialists.
 
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Related to Quantum Eraser: do entangled photons arrive at different moments?

1. What is a quantum eraser?

A quantum eraser is a thought experiment in quantum mechanics that demonstrates the concept of wave-particle duality. It involves a double-slit experiment where particles behave as waves until they are observed, at which point they behave as particles.

2. How does a quantum eraser work?

In a quantum eraser experiment, a pair of entangled particles are sent through a double-slit apparatus. One particle goes through one slit while the other goes through the other slit. The particles are then detected on a screen, creating an interference pattern. However, if the experimenter knows which slit each particle went through, the interference pattern disappears, and the particles behave as particles instead of waves.

3. What is the role of entangled photons in a quantum eraser experiment?

Entangled photons are used in a quantum eraser experiment to demonstrate the concept of quantum entanglement. These particles are connected in such a way that the state of one particle is dependent on the state of the other, regardless of the distance between them. This allows for the interference pattern to be affected by the experimenter's knowledge of which slit the particles went through.

4. Do entangled photons arrive at different moments in a quantum eraser experiment?

Yes, entangled photons can arrive at different moments in a quantum eraser experiment. This is because the particles are traveling through different paths and can experience different time delays. However, the time delay does not affect the entanglement between the particles, and they will still exhibit correlated behavior when measured.

5. What are the implications of a quantum eraser experiment?

A quantum eraser experiment challenges our understanding of reality and the role of observation in quantum mechanics. It suggests that the observer's knowledge and actions can affect the behavior of particles, and that particles can exist in multiple states simultaneously until they are observed. This has significant implications for fields such as quantum computing and cryptography.

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