Can Quantum States be Transferred without Knowledge of Initial Orientation?

Click For Summary

Discussion Overview

The discussion revolves around the possibility of transferring quantum states of photons between two experimenters, A and B, without B knowing the initial orientation of A's photons. It explores concepts related to quantum entanglement, teleportation, and the implications of measurement and interaction in quantum mechanics.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants suggest that if photons A and B are entangled, it may be possible for B to take the polarization states of A's photons without knowing their orientation.
  • Others argue that if the photons are not prepared from the same source, there may be no way to achieve entanglement or transfer of states.
  • One participant mentions that exchanging a photon between A's and B's sets could still result in entanglement.
  • Another participant raises the idea that the presence of a third party could collapse the wave function, impacting the transfer of states.
  • A participant introduces the concept of quantum teleportation, explaining that it requires a pre-fabricated entangled pair and involves classical communication to transfer quantum states.
  • There is a mention of the no-cloning theorem, which states that the original state is destroyed during the measurement process in quantum teleportation.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of transferring quantum states without prior entanglement. Some believe it may be possible under certain conditions, while others contend that it is not feasible if the photons are not from the same source. The discussion remains unresolved regarding the exact conditions under which state transfer could occur.

Contextual Notes

Participants note the complexities of quantum mechanics, including the role of measurement, entanglement, and the influence of external factors on quantum states. There are also references to the limitations of current understanding and the speculative nature of the proposed scenarios.

Who May Find This Useful

This discussion may be of interest to those exploring quantum mechanics, particularly in the context of quantum information theory, entanglement, and the implications of measurement in quantum systems.

Harmony
Messages
201
Reaction score
0
An experimenter, A, has prepared four photons with known polarization states. In another lab, experimenter B has prepared four photons with random orientation.

Is it possible, for the photons prepared by B, to take the polarization states of the photons prepared by A, without B knowing the orientation of the photons prepared by A?
 
Physics news on Phys.org
It depends on wheter the photons were pre pared from the same source that is if A and B have got entangled product then yes.Even if A knows B and B knows A and they know what the other is doing and their labs are not very far away again the answer (maybe) is yes.
 
yes,it will b
 
Is the uncertainity which Heisenberg talk of a result of complex interconnections between a particle to the rest of the universe all it is the inherent property of nature?
 
Hmm..that means if they aren't entangled before, there isn't anyway to make them entangled? Meaning that, if the photons are not prepared from the same source, there is absolutely no change for the transfer to occur?
 
No Its not that.If you exchange one photon from set of A to that of set set of B still there will be an entanglement.
Also If A performs experiment first or B, and tell the latter about his/her result still there will be entanglement due to B's (or A's)conciousness
 
Hmm...so would it be safe to say that, experimenter B can't "steal" the information from A without exchanging the photon or ask the information from A like you said?
 
They should also be situated far away so much so that their fields can't interact.Also their should be no third person knowing about them and their nature or else he/she shall collapse their wave function.Complete Sheilding (imposible in reality and might be in principle also.)
 
Deric Boyle said:
They should also be situated far away so much so that their fields can't interact.Also their should be no third person knowing about them and their nature or else he/she shall collapse their wave function.Complete Sheilding (imposible in reality and might be in principle also.)

Thanks for your help, I really appreciate it. The reason i ask about the transfer of states, is because that I plan to write a story which involved a "stolen" quantum states ie experimenter B steal the quantum states of photons from A and make the original photons randomly oriented.

I am aware that this might not be possible to do in practice, but i suppose there isn't any physics laws that forbids the re-entanglement of two set of photons which comes from different source (at least, base on current knowledge), since you said that in principle their field might interact?

I don't wish to write a science fiction story which is forbidden by the laws of physics, that's why i post in this forum for expert's advice...:)
 
  • #10
What you are asking about is called quantum teleportation. Look it up.
 
  • #11
Sorry to state this Sir Harmony I'm not an expert.I just took up quantum mechanics few weeks ago.
And K^2 I wasn't talking about quantum teleportation (by the way what is it?) I just gave what I interpret from quantum mechanic which is that the experiment which I perform at quantum level has a considerable dependence upon my intentions.
Sir Harmony please confirm from experts like A.Neumaier or tom.stoer
or our Mentor Doc Al
 
  • #12
I was replying to OP. Sorry, I can see now that it was ambiguous.

Quantum teleportation is a method for transfering quantum state using classical channel without performing a projective measurement on the state in question. You do need a pre-fabricated maximally entangled pair, however.

So, say Alice has an electron with some unknown spin state. She wants to send that spin state to Bob. They can use optic fiber to prepare a pair of entangled electrons in their respective labs. Alice can then perform a Bell-basis measurement of the pair of electrons she now has and send result of the measurement, which is two bits of information, to Bob via any convenient channel. Bob can use that information to restore the state of the original electron in Alice's lab. The original state is, of course, destroyed in the Bell-basis measurement, fulfilling requirements of the no-cloning theorem.

If you want the details of the algorithm with all the math, Wikipedia article covers all the basics, and links to relevant articles.

By the way, this has been experimentally confirmed on simple 2-state systems.
 
  • #13
Thanks K^2 :-)
 

Similar threads

High School Entanglement & Superposition Probabilities
  • · Replies 27 ·
Replies
27
Views
2K
Graduate Exact symmetry, quantum states, and symmetric dynamics
  • · Replies 8 ·
Replies
8
Views
1K
Undergrad Understanding Spin States in 2D Vector Spaces
  • · Replies 6 ·
Replies
6
Views
3K
Graduate What happens when entangled photons are split into different paths?
  • · Replies 41 ·
2
Replies
41
Views
7K
Graduate Is delayed choice remote entanglement of photons derived from TDSE?
  • · Replies 58 ·
2
Replies
58
Views
5K
Undergrad Entanglement swapping in the context of Indivisible Stochastic Process
  • · Replies 2 ·
Replies
2
Views
1K
Graduate Question: Unambiguous discrimination between two non-orthogonal states
  • · Replies 4 ·
Replies
4
Views
1K
Undergrad What happens to entanglement inside a polarizer?
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Is this a valid quantum Cheshire cat?
  • · Replies 13 ·
Replies
13
Views
2K
High School Entanglement, correlation and randomness
  • · Replies 18 ·
Replies
18
Views
3K