# Talk:Quantum teleportation

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## Alternative name

"Thus, despite the provocative name, it is best thought of as a kind of communication, rather than a kind of transportation."

It's a pretty terrible name, then. Has anyone proposed or used an alternative name that better connotes communication? If so, please put it in the intro to the article in bold. — Preceding unsigned comment added by 71.167.62.7 (talk) 21:55, 15 August 2013 (UTC)

Teleportation is a kind-of transportation. Although one can think of it as a kind-of communication, it is also, defacto, a kind of transportation. The article, as written, may be placing the empahsis incorrectly. The name is appropriate. User:Linas (talk) 17:25, 20 November 2013 (UTC)

When I read about Quantum Teleportation a year ago, I got that it was not about physical transportation, it was about information transportation. But there were no classical communication channel in the system then and I expected a kind of superluminal communication method if succeeded. Now after I read the introduction, it was as if I hit wall while running. Why the hell did they include classical Communication channel and try to transmit the state of the qbit to the other side ? OK lets say that's what they want to accomplish, that transmitting/transporting Quantum state themselves, but then why do they call it Quantum teleportation? It's a Quantum State Transport/Transmit. They are not testing states of the paired qbits which are at great distances from each other, try to change state of one and observe if the other's state changes as well. That would be Quantum Teleportation and which would be testing the essence of Quantum entanglement. This is quoted from Bell state : "Unlike classical phenomena such as the nuclear, electromagnetic, and gravitational fields, entanglement is invariant under distance of separation and is not subject to relativistic limitations such as the speed of light". So The name is not appropriate. What I have in mind for Quantum Teleportation is described in this article : http://hansonlab.tudelft.nl/teleportation/ . They probably achieved the first prototype for Quantum Teleportation. Fotte (talk) 15:24, 18 September 2014 (UTC)

## Mistake

From what I see, the gate that has to be applied by the receiver in the case where both measurements are 1 is wrong. It should really be

0 1


-1 0

= Z*X, which is what the circuit diagram indicates: First quantum NOT (X), then phase shift (Z).

If you go back up, you will find that the state in the respective case is "wrong" - it has a global phase -1, and should really be

-\beta|0> + \alpha|1>

I have derived the equations myself and got this. 213.142.168.211 (talk) 15:02, 29 August 2013 (UTC)Daniel

I just checked the formulas in the article, and they appear correct to me; I don't see the mistake that you describe. User:Linas (talk) 18:51, 21 November 2013 (UTC)

## There is no actual "Atom Teleportation"

The texts reads: "although single atoms have been teleported". That is plainly WRONG. If you read the papers used as reference and source, then it still is INFORMATION that is transported, not the actual atoms. Indeed it's not teleportation (of information) of atoms, but 'from atom to atom'. — Preceding unsigned comment added by 131.175.161.14 (talk) 09:58, 11 March 2014 (UTC)

I have corrected the error — Preceding unsigned comment added by 131.175.161.14 (talk) 10:03, 11 March 2014 (UTC)

## removed text from lead

I'm removing the frollowing text from the lead, because it is wrong, and is causing readers to miunderstand (see some of the comments and essays above).

Quantum teleportation is unrelated to the kind of teleportation commonly used in fiction, as it does not transport the system itself, does not function instantaneously, and does not concern rearranging particles to copy the form of an object. Thus, despite the provocative name, it is best thought of as a kind of communication, rather than a kind of transportation.

First of all, it is related, because it does transport the system itself! This follows from axiomatizations of QM, which basically state that the universe consists of bits and qubits; and there are two ways of moving a qubit: putting it on a horse and riding it somewhere, or quantum-teleporting it. Teleportation is a kind-of transport, this follows from the no-cloning/no-deleting theorems. True, it does not not function super-luminally (the no-communication theorem). It does concern re-arranging particles, although so far, we've only been able to re-arrange only two or three, and not even an entire atom, yet. Yes, it can be thought of as a kind-of communication, but it is also quite correct to think of it as a kind-of transportation. User:Linas (talk) 17:37, 20 November 2013 (UTC)

I also added a five-paragraph non-technical summary, which perhaps will help prevent mistakes like the above in the future. If there are other things that need to be explained in a non-technical way, give me a ping. User:Linas (talk) 20:15, 20 November 2013 (UTC)

It's not really correct to say that the universe is composed of bits and qubits. I understand the sentiment, but if you want to idealize the universe as a computer, then really the qubits are fundamental and bits are emergent, corresponding to qubits that are decohered. The reference to the no-communication theorem is also not quite right; qubits can carry information (in fact one bit per qubit) but the theorem refers instead to the impossibility of using entanglement for instantaneous communication. I'll do some rewriting of this soon, but am happy to discuss more here first if anyone wants. 24.61.8.127 (talk) 04:12, 14 December 2013 (UTC) (this last change I accidentally made w/o being signed in. Here is my real signature. Aram.harrow (talk) 04:14, 14 December 2013 (UTC))

The explanation is missing references and it sounds like original research, with too fancy expressions. Mstuomel (talk) 03:26, 30 January 2014 (UTC)
I have some concerns about it too, particularly the claim that qubits cannot encode bits (at all), which seems to contradict most reliable sources on quantum computing. I note that the editor who added the text (Linas) is/was blocked indefinitely, although on behavioral issues [1]. The text was added in violation of WP:BLOCKEVASION although that's the least of the concerns here. JMP EAX (talk) 06:58, 23 August 2014 (UTC)
If one wants to write something "non-technical" the bullet list from [2] appears a better source. JMP EAX (talk) 09:04, 23 August 2014 (UTC)
As for interpretations this article is rather one-sided. For more see [3] JMP EAX (talk) 09:42, 23 August 2014 (UTC)

## What Happened to Ted?

So far, the article mentions three "people" who are hypothetically examining and "teleporting" quantum state information, "Alice," "Bob," and "Carol."

Those of us who were at least teenagers in 1969 remember Bob & Carol & Ted & Alice, which its wikipedia article describes as a "1969 comedy-drama film" about two married couples who almost have a foursome in bed.

Does the inclusion of "Carol" in the description reflect wider usage in the QM community (I've seen "Alice" and "Bob" used throughout papers on quantum teleportation to identify hypothetical observers of quantum states in discussions of quantum teleportation, and the authors of the June 3 TU Delft paper on "unconditional quantum teleportation" actually name their quantum teleportation devices "Alice" and "Bob" [1]), or was it just a bit of humor on the original editor's part, alluding to the film I described? loupgarous (talk) 02:15, 10 June 2014 (UTC)

They are common names used in cryptography and physics. Carol is the classic third participant. Eve is commonly the eavesdropper. See Alice_and_Bob. 134.134.137.73 (talk) 21:35, 11 June 2014 (UTC)

## Local explanation of the phenomenon, Classical Transport Channel, Superluminal Communication, Need for a Revise on the Page

On the Local explanation of the phenomenon part, there is a quote from a paper from 1999 , by David Deutsch and Patrick Hayden , stating that Quantum information traveling though classical channel and surviving decoherence is the basis of Quantum Teleportation. this is the link to the paper (quote is from the end of page 13) : http://arxiv.org/ftp/quant-ph/papers/9906/9906007.pdf . The problem is that this quote is from the Information flow in Einstein-Podolski-Rosen experiments part. That experiment is indeed using classical transport channel to carry QBits. But full quote ends like this: "..surviving decoherence, is also the basis of quantum teleportation , a remarkable phenomenon to which we now turn" meaning Einstein-Podolski-Rosen experiments provides a basis for Quantum Teleportation and the author explains it in the next chapter : ' 5. Information Flow in the Quantum Teleportation '. I'm quoting the opening part of the chapter. You can check for yourselves from the link I gave above. " The very term ‘teleportation’ was chosen by the discoverers of the phenomenon (Bennett et al. (1993)) because it was deemed to be a spectacular example of information from one location A appearing at another location B without being carried there in any physical object travelling from A to B –i.e. without information flow." So even the referenced scientist defines it as information teleportation without information being carried to the target location in any physical object. Also in this link : http://hansonlab.tudelft.nl/teleportation/ , you can find a recent experiment in which they used intentionally defective diamonds to trap electrons and used them to test Quantum Teleportation. They succeeded over 3 meters ,if I didn't read it wrong, they are preparing another experiment to test it over a long distance. So in essence, we need to revise this page to reflect what Quantum teleportation really is. I appreciate help on this matter. Fotte (talk) 08:09, 22 September 2014 (UTC)