Live data from Hacker News

Researchers quantum teleport particle of light six kilometres

sciencebulletin.org

21–30 of 219 posts

Re: Researchers quantum teleport particle of light six kilometres

#21
Awesome. So a quantum network would have the photon act as a data stream, in a way it would act like a physical security key. So with a lot of work, this would be amazing for 1:1 communications. But what if I want to send my dick pick to hundreds of people at once(1:100 distribution)? Is it possible to entangle one photon with multiple?

Re: Researchers quantum teleport particle of light six kilometres

#22
post #19

The title of the article, while probably not intentional clickbait, is incorrect. Only the quantum state of the photon was "teleported", not the photon itself. The original photon was in fact destroyed, and only the information about its state was transmitted.

> The original photon was in fact destroyed, and only the information about its state was transmitted. Isn't that how teleportation works in, for example, Star Trek? https://www.youtube.com/watch?v=nQHBAdShgYI

Funny you say that. When I read this for the first time, I had a flashback of Bones complaining about having his molecules scattered over space :)

Re: Researchers quantum teleport particle of light six kilometres

#23
post #13

The title of the article, while probably not intentional clickbait, is incorrect. Only the quantum state of the photon was "teleported", not the photon itself. The original photon was in fact destroyed, and only the information about its state was transmitted.

This is the exact meaning of quantum teleportation: https://en.wikipedia.org/wiki/Quantum_teleportation Changing the title to "Researchers quantum teleport particle..." would make it clearer. On the other hand, as far as I understand quantum mechanics, there is nothing about the "original" photon that was not teleported/transferred to the new location. It would be impossible to create an experiment that could conclud…

OK, we've updated the title. Thanks!

Re: Researchers quantum teleport particle of light six kilometres

#24
post #13

Earlier quoted context omitted.

This is the exact meaning of quantum teleportation: https://en.wikipedia.org/wiki/Quantum_teleportation Changing the title to "Researchers quantum teleport particle..." would make it clearer. On the other hand, as far as I understand quantum mechanics, there is nothing about the "original" photon that was not teleported/transferred to the new location. It would be impossible to create an experiment that could conclud…

Does the teleportation happen at the speed of light? Was inspired by Regetti's Startup School talk and have almost zero background :p

Quantum teleportation requires classical communication from the sender to the receiver of the state. Whether the teleportation itself happens faster then the speed of light is up to your interpretation of Quantum mechanics. The important part is that it does not allow information (classical or quantum) to be transmitted faster then light.

Re: Researchers quantum teleport particle of light six kilometres

#25
post #13

Earlier quoted context omitted.

This is the exact meaning of quantum teleportation: https://en.wikipedia.org/wiki/Quantum_teleportation Changing the title to "Researchers quantum teleport particle..." would make it clearer. On the other hand, as far as I understand quantum mechanics, there is nothing about the "original" photon that was not teleported/transferred to the new location. It would be impossible to create an experiment that could conclud…

Does the teleportation happen at the speed of light? Was inspired by Regetti's Startup School talk and have almost zero background :p

No, the information is transferred classically to the location, but copied quantumlly.

Re: Researchers quantum teleport particle of light six kilometres

#26

Teleportation is not possible. Quantum teleportation is the transmission of the exact state of a photon from one place to another. Still, even this happens at less than the speed of light. Otherwise it would violate causality. The media plays fast and loose with terminology either out of plain ignorance or the desire to sell a story.

> Teleportation is not possible. Quantum teleportation is the transmission of the exact state of a photon from one place to another. Still, even this happens at less than the speed of light. Otherwise it would violate causality.

Maybe I'm remembering my QED special topics class incorrectly, but I thought the state teleportation is believed to be instant. The problem is to extract the state information, the transformation operators still need to be communicated. So you still have to get on the phone to tell your colleague across the planet what to do to see the entangled result. It's been years, so maybe I'm a little off on that?

Causality also isn't a hard-and-fast law. We've just never seen it violated before. It's one of those physics problems that is really hard to find evidence to support or discredit it.

Re: Researchers quantum teleport particle of light six kilometres

#28
I posted this in a duplicate thread:

For those thinking that this is a step towards faster-than-light (FTL) communication: As far as I know it's fairly certain that quantum entanglement will not allow for FTL communication. Basic principle is that while measurements between both sides will be correlated, it's not possible to tell how they are correlated until both sides compare measurements.

https://en.wikipedia.org/wiki/Superluminal_communication#Qua...

http://physics.stackexchange.com/a/203893

Given that, it seems like the touted benefit of using quantum entanglement here is in securing communications, since your measurements will no longer correlate if a third party is also measuring? At least, that's what I gathered.

Re: Researchers quantum teleport particle of light six kilometres

#30

Teleportation is not possible. Quantum teleportation is the transmission of the exact state of a photon from one place to another. Still, even this happens at less than the speed of light. Otherwise it would violate causality. The media plays fast and loose with terminology either out of plain ignorance or the desire to sell a story.

>this happens at less than the speed of light.

Why can't it happen simultaneously? Why is distance relevant in this case?

Post reply on HN