Entangled Photon Measurements: A(t) = d/c and B(t) = 5d/c

Click For Summary

Discussion Overview

The discussion revolves around the behavior of entangled photons, specifically focusing on the implications of distance between detectors on the observed correlations of their polarization states. Participants explore the nature of entangled photon measurements in different experimental setups, including the effects of distance on the timing of measurements and the persistence of anti-correlations in polarization states.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant describes an experimental setup with entangled photons sent to two detectors, A and B, at equal distances, noting that measurement at A determines the polarization of the photon at B due to their entangled nature.
  • Another participant questions whether perfect anti-correlations would still hold if the distances to detectors A and B are unequal, specifically with A at d and B at 5d.
  • There is a proposal regarding the oscillation of photons in a horizontal/vertical superposition state, suggesting that they oscillate continuously from creation to detection.
  • A counterpoint is raised, arguing that it is incorrect to say that photons oscillate in this manner, emphasizing that linearly polarized light remains polarized in a non-birefringent medium and that correlations do not depend on the path difference between photon paths.

Areas of Agreement / Disagreement

Participants express differing views on the implications of distance on the anti-correlations of entangled photons and the nature of their oscillation. There is no consensus reached on these points, indicating ongoing debate and exploration of the topic.

Contextual Notes

The discussion includes assumptions about the behavior of entangled photons and the effects of measurement timing, which may depend on specific experimental conditions not fully detailed in the posts.

Point Conception
Gold Member
Messages
1,157
Reaction score
1,866
Entangled photons in superposition state : | Ψ} = (|HV} - | VH})/1/√2 are sent from source to polarizers and then to detectors A and B ( in this setup distance from source to detectors is equal). If A measures vertical photon she knows immediately that B photon must be horizontally polarized.
After the stream of random polarized photons at A and B, are compared for time at detectors being equal
the entangled anti correlated pairs of photons are observed.
In another experimental setup with entangled photons prepared the same way the distance from source to detector A = d and distance from source to detector B = 5d.
Then one of the entangled pair is measured at A(t) = d/c and the other is measured at B(t) = 5d/c
Would you expect that the perfect anti correlations for the entangled pair of photons
to hold in second case ?
 
Physics news on Phys.org
morrobay said:
Would you expect that the perfect anti correlations for the entangled pair of photons
to hold in second case ?
Yes. Why do you think it wouldn't?
 
When the pair of entangled photons are in horizontal/vertical superposition is it correct to say that each photon of the pair is oscillating , ie. HVHVHVHVHV...
From time of creation at source until detection ?
 
morrobay said:
When the pair of entangled photons are in horizontal/vertical superposition is it correct to say that each photon of the pair is oscillating , ie. HVHVHVHVHV...
From time of creation at source until detection ?
No, it's not correct to say that. Linearly polarized light stays linearly polarized in non-birefringent medium. And when you detect one photon from entangled pair the other photon's polarization can be predicted in the same basis no matter when you detect it. In your model correlations would depend on path difference between two photon paths. But no such thing is observed in experiments.
 
  • Like
Likes   Reactions: vanhees71

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 41 ·
2
Replies
41
Views
6K
  • · Replies 27 ·
Replies
27
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 58 ·
2
Replies
58
Views
5K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 61 ·
3
Replies
61
Views
5K
  • · Replies 19 ·
Replies
19
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K