3-way+ Quantum Entanglement

[Fed]

I have read in places that this is not outside the realm of possibilities but the details are pretty vague, can anyone elaborate if this would be similar to normal 2 particle quantum entanglement?

 

what i mean is, with 2 particel QE and enough computing power wtc we know it is possible to "teleport" the information i contain to another predetermined location, would this work with 3-way+ QE?

 

for instance, in this case would there now be 2 of me that are recreated, essentially giving me a "Quantum Twin"?

 

the reason i ask is not because i want there to be 2 of me, but rather, if this is correct, it could essentially eliminate world hunger and any such resource deficiency we may have once manipulating QE can be done on a more major scale

[swansont]

I have not read anything about 3-way entanglement, and can't think of how it might work. Any links?

 

the reason i ask is not because i want there to be 2 of me, but rather, if this is correct, it could essentially eliminate world hunger and any such resource deficiency we may have once manipulating QE can be done on a more major scale

How would this have any effect on world hunger or resource deficiency? Entanglement and teleportation deal with state information, and the original system's information is destroyed. I can't think of how you might make 2 copies of the information without violating the no-cloning theorem.

http://en.wikipedia.org/wiki/No-cloning_theorem

[imatfaal]

I have read in places that this is not outside the realm of possibilities but the details are pretty vague, can anyone elaborate if this would be similar to normal 2 particle quantum entanglement?

 

what i mean is, with 2 particel QE and enough computing power wtc we know it is possible to "teleport" the information i contain to another predetermined location, would this work with 3-way+ QE?

 

for instance, in this case would there now be 2 of me that are recreated, essentially giving me a "Quantum Twin"?

 

the reason i ask is not because i want there to be 2 of me, but rather, if this is correct, it could essentially eliminate world hunger and any such resource deficiency we may have once manipulating QE can be done on a more major scale

 

Unfortunately the quantum teleportation of information does not work like that - in the most basic of terms the information of the state is shifted from one end of a pair to the other end of a pair (no matter what the distance). But the no cloning theorem means that there is no possible duplication of an unknown arbitrary quantum state - and most interesting states will be unknown cos otherwise they have been measured and now are classical probabilities.

 

The bit where you say "we know it is possible" is actually the opposite of the truth. Quantum teleportation is incredible - and allows the transfer of an arbitrary amount of information about a quantum state to be transferred with a minimal overhead (a few classical bits of information); but it is most certainly not the creation of an identical copy a large distance away.

 

x-posted with swansont

Edited September 12, 2013 by imatfaal
xpost

[Fed]

yes, i am aware that the original is destroyed, but the information it contained is then sent through the entangled state and recreated using what was the entangled "twin" of the particle that sent the information.

 

my question is that they are not entangled "twins" but rather entangled "triplets" would this information be sent to both remaining entangled particles or just one of them?

 

ill find the page i read about 3-way entanglement and link it here

 

(apologies for my lack of terminology, but i am trying very hard to explain my query as accurately as possible)

http://physics.stackexchange.com/questions/54366/three-particle-quantum-entanglement'>The Link to where i read about 3 way QE

http://physics.stackexchange.com/questions/54366/three-particle-quantum-entanglement

 

this is where i first read about 3way QE

[imatfaal]

Well quantum computation (which that page is talking about) definitely theorises more than 2 qubit (quantum bit) entanglement and has algorithms which basically run up to n qubit entanglement - but I am unsure how much of this is presently realisable; I believe very very little. At present we can build and utilise classical gates (NOT AND etc) to a ridiculous complexity - however I think it is at the very cutting edge to even manipulate qubits in the real world and whether we can actually build Hadamard and CNOT gates, for a quantum circuit which would entangle as many qubits as you fancied, is something I would have to read up upon.

 

Briefly it is not a panacea for commodity shortages.

[Fed]

Also, swansonet, very offtopic but i thank you for your reply but the page you refer me to is too matmatically complex for me to understand

 

however, i am not totally mathmatically challenged and i would be more than interested in expanding my mathmatical knowledge so that i may understand it. i realise this would take time to learn but am well up to the challenge. could you please direct me somewhere so that i may learn the meaning of the many different formulae this topic requires

 

(i.e: e=mc2 is energy = mass x speed squared, e=energy, m=mass, c=speed. but this is as much as i know if you exclude global mathmatical terms (pi etc) and would like to expand my knowledge in this area

[Enthalpy]

I'd bet entanglement among 3 particles is possible and even common.

 

Imagine an idealized case where two successive transitions 3s -> 2p -> 1s of an atom emit a pair of photons. The orientation of the intermediate 2p state (between the spherical 3s and 1s) defines the polarization and direction of both photons, but loosely so - as much as an atom is directional, and it's as little directional as a small antenna, with an E pattern as a cosine of the elevation versus the first photon direction.

 

The path of the second emitted photon won't be perpendicular to the first one, but it can have an angle. The pair of photons cumulate a net recoil, which is compensated by the movement of the emitting atom.

 

In this case, the sum of momentums of two photons and an atom is zero, but the directions of both photons is largely undetermined - I'd say that two photons and an atom are entangled.

 

Depending on the situation, one or two constraints could limit the possible behaviours of three particles.

 

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What about quantum cascade lasers? They rely on a superlattice in a semiconductor to offer many energy levels to electrons, spaced precisely equal so that every transition can lase in the unique cavity and in accord with the other transitions. That way, one single electron from the power supply injected in the diode makes some 20 transitions, to emit ideally 20 infrared photons.

 

The photons are linked in some way, for instance through the momentum of the electron in the intermediate levels. If (unsure!) the electron isn't much pushed when in the intermediate levels, you get 20 photons linked somehow, say in their direction.

 

The intermediate levels have some width in a superlattice, so the energies of the photons are somewhat fuzzy, but their sum is constrained by the total energy height of the superlattice - again an entanglement, this time on energy. Even partial sums of energy are constrained, but with a tolerance. This supposes that the crystal keeps the electron's energy untouched for long enough.

 

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Please take with caution.

[swansont]

Was just reading about this, and n>2 particle entanglement is a thing. They (or at least this method) are called GHZ states.

 

http://en.wikipedia.org/wiki/Greenberger–Horne–Zeilinger_state

[MirceaKitsune]

Never heard about about more than 2 particles getting tangled myself. Neither that it should be possible nor that it shouldn't... so no idea.

 

As for entanglement being usable as a means of instant communication, my personal opinion is that soon enough entanglement should make it possible to create "instant walkie-talkie telegraphs". I really hope this happens before Mars One sends people to Mars and the like, as such should make it possible to talk to anyone at any distance with virtually 0 lag. If >2 way entanglement is possible too, this will certainly mean a new age for the internet... where the concept of connection speed should vanish entirely, and neither wires nor radio are needed to connect online.

[swansont]

As for entanglement being usable as a means of instant communication, my personal opinion is that soon enough entanglement should make it possible to create "instant walkie-talkie telegraphs".

 

There's no physics to back this up, and what we know tells us this can't work.

[MirceaKitsune]

 

There's no physics to back this up, and what we know tells us this can't work.

 

I see. From what I heard, entanglement means that if you give one particle a certain spin, the other one will have an opposite spin. So if someone could make a device that detects and translates changes in a particle's spin as binary data (zeroes and ones) I imagined it would work out.

[swansont]

 

I see. From what I heard, entanglement means that if you give one particle a certain spin, the other one will have an opposite spin. So if someone could make a device that detects and translates changes in a particle's spin as binary data (zeroes and ones) I imagined it would work out.

 

No. You can make the spins correlate, but you don't know what they are until you measure one of them. No way to use that the way you are describing.