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quantum teleportation has happened?

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Thu, 2014-06-05 03:18

#1

OneTrikPony OneTrikPony's picture

OneTrikPony's picture

quantum teleportation has happened?

Just got this from gizmag http://www.gizmag.com/teleport-quantum-information/32352/ Here's the paper http://m.sciencemag.org/content/early/2014/05/28/science.1253512

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Mea Culpa: My mode of speech can make others feel uninvited to argue or participate. This is the EXACT opposite of what I intend when I post.

Thu, 2014-06-05 06:22

#2

Lorsa

Lorsa's picture

I have some problems

I have some problems accessing the actual article, maybe it will be easier from the university. Sounds like it could potentially be awesome, but also... [color=lime]It's the end of the world! Scientists are going to destroy it! We need to stop the madness![/color] Sorry... someone has to say it. :)

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Lorsa is a Forum moderator [color=red]Red text is for moderator stuff[/color]

Thu, 2014-06-05 13:17

#3

OneTrikPony OneTrikPony's picture

OneTrikPony's picture

I havn't read the article

I havn't read the article either. I just provided the link for those who might have accademic access. Its true that we now have half the means to violate causality. Lucky that at this time we cant get qubits out of our light cone.

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Mea Culpa: My mode of speech can make others feel uninvited to argue or participate. This is the EXACT opposite of what I intend when I post.

Thu, 2014-06-05 13:22

#4

Leng Plateau Leng Plateau's picture

Leng Plateau's picture

I am the Eschaton. I am not

I am the Eschaton. I am not your god. I am descended from you, and I exist in your future. Thou shalt not violate causality within my historic light cone. Or else.

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At least with Lovecraft, nobody pretends the gods are nice. And wherever you end up, there is guaranteed to be tentacles.

Thu, 2014-06-05 17:54

#5

OneTrikPony OneTrikPony's picture

OneTrikPony's picture

Actually, what are the

Actually, what are the implications for real world tech and society? Is this more than a fancy zero latency radio with realy expensive band width?

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Mea Culpa: My mode of speech can make others feel uninvited to argue or participate. This is the EXACT opposite of what I intend when I post.

Thu, 2014-06-05 18:48

#6

Pyrite

Pyrite's picture

In the short term: not much.

In the short term: not much. It's a very preliminary technological breakthrough. In the mid term: Instant, impossible to intercept, unjammable communications will likely have important military and espeonage applications, and eventually even business applications. In the long term: deep space probes rigged with QE comms exploring the universe and giving us information back in real time. In the very long term: Eclipse Phase style egocasting to explore distant worlds and seed them with humanity. Ships full of colonists that never need to lose contact with home.

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'No language is justly studied merely as an aid to other purposes. It will in fact better serve other purposes, philological or historical, when it is studied for love, for itself.' --J.R.R. Tolkien

Thu, 2014-06-05 18:58

#7

Smokeskin

Smokeskin's picture

Instant comms would be a big

Instant comms would be a big deal in high frequency trading also.

Thu, 2014-06-05 21:22

#8

OneTrikPony OneTrikPony's picture

OneTrikPony's picture

Any one know the lower bound

Any one know the lower bound on energy and time needed to create qbits? Also what is the potential lower bound on data density for physical volume and mass? Are we going to see an entangled version of the current cellular system in the future?

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Mea Culpa: My mode of speech can make others feel uninvited to argue or participate. This is the EXACT opposite of what I intend when I post.

Thu, 2014-06-05 21:46

#9

MAD Crab

MAD Crab's picture

Science to the rescue

This is not instant communication. To the best of scientific knowledge, there is no way to transfer information faster than light. I have to stress this, because a lot of people hear "quantum teleportation" and get very excited. I suggest reading the Wikipedia page to get an idea of what they're actually talking about. What this -can- be used for is tamper-proof point-to-point encryption. Leng, what is the name of that series? I've read one book, and for the life of me I cannot remember the title...

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Thu, 2014-06-05 21:53

#10

Leng Plateau Leng Plateau's picture

Leng Plateau's picture

It's by Charles Stross MAD.

It's by Charles Stross MAD. The books in that series are Singularity Sky and Iron Sunrise. He stopped writing that series after Iron Sunrise due to having written himself into a corner (according to Stross). Very good books aside from a couple continuity glitches and one very problematic scene.

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At least with Lovecraft, nobody pretends the gods are nice. And wherever you end up, there is guaranteed to be tentacles.

Thu, 2014-06-05 21:57

#11

MAD Crab

MAD Crab's picture

Let's iron bomb the sun and be done with unfinished series

Arg. Then I've probably read both, not just the one. Hate it when a series is dropped without resolution!

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Thu, 2014-06-05 23:33

#12

Erulastant Erulastant's picture

Erulastant's picture

I haven't read the article

I haven't read the article (right now I have only my smartphone for internet and reception isn't great) but according to current theory there's no way to control the information that's sent over an entanglement link, so like MAD said, it'll mostly just be for encryption. IIRC, a pair of qubits could be made for about 200eV, which is pretty small (but then again, that's just for one pair). It might be able to go lower than that, (in theory arbitrarily low if you're using low-frequency paired photons, but I can't figure off the top of my head how to reliably produce those) but for easily storable qubits I don't think you'll get much lower. For more detail, I did a post in the general discussion forum (Bibliophile's thread, on qubit manufacturing. I'd link it, but as mentioned, shitty internet). The big thing with qubits is figuring out how to store then without ruining them. I'm actually working in a lab with qubits this summer, ours have a lifetime of a few seconds and that's considered to be, if not cutting edge, pretty damn good. Sometimes I feel like my entire job on this forum is to quash people's hopes about QE comms.

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You, too, were made by humans. The methods used were just cruder, imprecise. I guess that explains a lot.

Fri, 2014-06-06 01:05

#13

OneTrikPony OneTrikPony's picture

OneTrikPony's picture

Erulastant;

Erulastant; Thanks for going to the effort to reply. Here's a quote from the gizmag article " In this case, the team teleported information contained in one quantum bit (or qubit, the quantum analog of a standard computer bit) to a completely separate quantum bit, using specially-designed computer chips. Each chip featured a synthetic diamond to contain the entangled electrons and several nitrogen atoms. Data was then encoded for transmission in the transmitting diamond’s nitrogen atom as alterations of the spin of the electron. The electron in the receiver diamond then showed the opposite of that manipulation at precisely the time that the transmission was "sent." "We use diamonds because 'mini prisons' for electrons are formed in this material whenever a nitrogen atom is located in the position of one of the carbon atoms," explained Hanson. "The fact that we're able to view these miniature prisons individually makes it possible for us to study and verify an individual electron and even a single atomic nucleus. We're able to set the spin (rotational direction) of these particles in a predetermined state, verify this spin and subsequently read out the data."

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Mea Culpa: My mode of speech can make others feel uninvited to argue or participate. This is the EXACT opposite of what I intend when I post.

Fri, 2014-06-06 14:50

#14

Erulastant Erulastant's picture

Erulastant's picture

OK, I'm at work with real

OK, I'm at work with real internet now, and I have access to the original paper, so I'm giving it a look. So the first thing I notice is "To teleport the quantum state Alice performs a joint measurement on her qubits (qubits 1 and 2) in the Bell basis, projecting Bob’s qubit into a state that is equal to |[psi]> up to a unitary operation that depends on the outcome of Alice’s measurement. [b]Alice sends the outcome via a classical communication channel to Bob, who can then recover the original state by applying the corresponding local transformation.[/b]" And in a bit plainer English, from the abstract, "Nevertheless, quantum information can be faithfully transmitted over arbitrary distances through quantum teleportation provided the network parties (named “Alice” and “Bob”) have previously established a shared entangled state and [b]can communicate classically (8–11).[/b]" So while this is, in fact, quantum communication of meaningful information, it's not usable for any sort of FTL communication because the users must be able to communicate classically. This is basically just the quantum encryption scheme, just run backwards (Where the 'encryption key' is sent classically and the 'encrypted data' is sent quantumly, which is dreadfully inefficient once you start trying to send large amounts of information. Except that the 'encrypted data' in question is quantum information, which doesn't make it any more useful practically, but [i]is[/i] much more useful as a part of the setup for other QM experiments.) Anyways, sadly, no FTL from this.

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You, too, were made by humans. The methods used were just cruder, imprecise. I guess that explains a lot.