Complex quantum teleportation achieved for the first time

https://phys.org/news/2019-08-complex-quantum-teleportation.html

by lelf • 7 years ago

98 60 7 years ago

phys.org

lota-putty• 7 years ago

1. Size of the Particle teleported?

2. Displacement distance & velocity?

3. Energy consumed?

Edit:

4. Is it really a teleportation?

nine_k3• 7 years ago

«Austrian and Chinese scientists have succeeded in teleporting three-dimensional quantum states for the first time»

So, no particles were moved, it's just cloning the state of one particle to another. It's also important, but it's not something like the "beam me up" type of teleportation.

Koshkin2• 7 years ago

But aren't elementary particles of the same kind only distinguishable by their state?

antisemiotic• 7 years ago

This is exactly what "quantum teleportation" means and it has never meant anything else. "Beam me up" is pure fantasy.

archgoon3• 7 years ago

It's transferred, not cloned (which implies a copy). If you could clone quantum states; then you'd get FTL communication.

chrischen• 7 years ago

Technically in Star Trek I believe transporters recreated you at the destination, and no particles were moved either.

krilly• 7 years ago

That is the definition of teleportation in every scifi setting I know of

empath75• 7 years ago

There’s nothing that distinguishes two particles that share a quantum state. You can’t say it’s the same particle and you can’t say it’s not.

jarfil• 7 years ago

1. None (the size of a photon).

2. Short & speed of light.

3. Irrelevant, since this is about whether it was actually doable, not about doing it efficiently.

4. The output particle is impossible to distinguish from the input one, but it didn't travel from input to output, so... how else would you define "real" teleportation?

real-teleports• 7 years ago

  how else would you define 
  "real" teleportation?

As something other than such a ridiculous game of 3 card monte. That's all this has ever been.

Put a red marble and a blue marble in a sock, and then close your eyes and withdraw one marble from the sock. Place it in a mitten, and send the mitten to a friend.

Then we claim that the person who looks at their marble first has defined the reality of the other by default, and that qualifies as teleportation?

Teleportation has been demonstrated as a thought experiment countless times, and this doesn't pass the smell test. The concept of teleportation is instantaneous transportation of physical objects with mass and volume across arbitrarily large distances, seemingly as if stopping time and stepping through a door that connected point A and point B, in order to skip over the effort of transiting real physical distance.

This concept may be unrealistic, but we don't squat on antiquated terms like luminiferous ether when we conceptualize quantum foam.

There's this academic inertia to opportunistically squat on a word with a loaded meaning, all to gain favor and generate buzz and hype.

People desperately want recognition for a contrivance by leaning on a word. They know that using the word "teleportation" to describe something less exciting will provoke magical thinking among outsiders.

Since this process cannot produce effects faster than light, it's not even a slight improvement beyond radio or lasers or any form of radiant communication.

People don't refer to these efforts appropriately. The objective of these experiments is tamper evidence for quantum communication channels, and nothing more.

virgil_disgr4ce• 7 years ago

"Teleportation" is such a misleading term. Information (in the form of a quantum state) is transmitted, not matter. And it requires a lot of setup and preparation including classical transmission as well.

bentona• 7 years ago

How else would we teleport matter, if it wasn't via information representing that matter?

abdullahkhalids2• 7 years ago

The original discoverers [1] - a really smart bunch - used the full term "teleportation of an unknown quantum state", which is correct. Subsequent work has been lazy in their terminology. [1] is also 100% clear about the resources needed in the title.

[1] https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.70...

krapp3• 7 years ago

On why "quantum teleportation" can't be used for faster-than-light communication:

https://physics.stackexchange.com/questions/155913/quantum-t...

https://www.askamathematician.com/2013/01/q-what-is-quantum-...

https://medium.com/starts-with-a-bang/ask-ethan-can-we-use-q...

ahelwer2• 7 years ago

On why entanglement in general cannot be used for FTL communication, BUT you can get some FTL "correlations" out of it which are impossible with purely classical methods: https://medium.com/@ahelwer/walking-the-faster-than-light-ti...

jerf• 7 years ago

Nice of them to decide to call this "multidimensional quantum teleportation" too. We'll be chasing the "OMG whatif scientists teleport in monsters from other dimensions didn't anyone play doom" fire down for the next 20 years.

gibspaulding• 7 years ago

What sort of technologies could (theoretically) be built relying on "quantum teleportation"?

anchpop2• 7 years ago

Uninterceptible communication would be one application

AlexDragusin• 7 years ago

First known teleportation device was called the Fax which brings us to the reality that teleportation can be achieved by transferring the information through space rather than translation through space as most people imagine it.

This, once reality (at human scale), will bring an important ethical dilemma since for a short time there will be 2 of the same person, which for all intents and purposes are the same, even more so than cloning. Obviously, after transfer is complete, the source would have to be killed.

For non organic matter this could be great and perhaps the basis of some sort of matter to energy converter (it takes energy to create the duplicate), in time, storing the information of stuff you have transferred in a database can do without the initial step, and simply recreate the stuff.

As with any tech, there is a double edge sword to be mindful of.

Be careful what you wish for then push that teleport button as needed.

viach• 7 years ago

Interesting, is this teleportation thing restricted only by space or particles can also be tangled being in different time periods?

TheRealPomax5• 7 years ago

It's only called teleportation, it has nothing to do with teleporting matter in the sci-fi sense.

Quantum teleportation is about preparing two particles so that that by destroying the original particle's state by measuring it, and then transmitting a specific bit pattern as regular information, constrained by the speed of light, the other particle can be made to have the identical quantum state as was measured on the now destroyed particle.

The quantum state is (destructively) "teleported" from one particle onto another (preallocated) particle, obeying the rather mundane rules of classical physics.

logicprog• 7 years ago

In theory, could that be used on a block of random matter and a, say, banana, so that you can get lightspeed transmission of banana-ness?

tunesmith3• 7 years ago

How is that different or better than just transmitting information at light speed over fiber? Excuse the ignorant question.

atrandom• 7 years ago

how did they get from this to quantum internet in once sentence?

ahelwer2• 7 years ago

In contrast to conventional internet where classical 1s and 0s are transmitted via some medium like copper or fiber optics or radio waves, qbit states are far too fragile to survive such transportation and so would be transmitted via the quantum teleportation protocol.

Physical networking infrastructure will still be necessary; teleporting a qbit requires a pre-existing entangled qbit pair in addition to two bits of classical information, so you'll need some method of sending one half of an entangled qbit pair to the recipient. It's okay if this process is lossy, because you can easily generate & re-send an entangled qbit if it gets lost. Once you successfully manage to get the entangled qbit through, you can use it to teleport the qbit you actually want to send (whose state is presumably the product of some long, expensive computation and therefore far too valuable to risk sending via such a lossy channel).

Jeff_Brown• 7 years ago

In a nutshell, why are we trying to do this?

tunesmith3• 7 years ago

maybe... ultra-secure communication of very large data?

Complex quantum teleportation achieved for the first time

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