Mathematical Breakthrough Sets Out Rules For More Effective Teleportation

dsinc sends this news from the University of Cambridge: "For the last ten years, theoretical physicists have shown that the intense connections generated between particles as established in the quantum law of ‘entanglement’ may hold the key to eventual teleportation of information. Now, for the first time, researchers have worked out how entanglement could be 'recycled' to increase the efficiency of these connections. Published in the journal Physical Review Letters, the result could conceivably take us a step closer to sci-fi style teleportation in the future, although this research is purely theoretical in nature. ... Previous teleportation protocols have fallen into one of two camps, those that could only send scrambled information requiring correction by the receiver or, more recently, "port-based" teleportation that doesn't require a correction, but needs an impractical amount of entanglement – as each object sent would destroy the entangled state. Now, physicists from Cambridge, University College London, and the University of Gdansk have developed a protocol to provide an optimal solution in which the entangled state is 'recycled,' so that the gateway between particles holds for the teleportation of multiple objects. They have even devised a protocol in which multiple qubits can be teleported simultaneously, although the entangled state degrades proportionally to the amount of qubits sent in both cases."

Comments

"More effective teleportation"!?!?!?!

[Anonymous Coward]

Bit optimistic, aren't we?

Re: "More effective teleportation"!?!?!?!

[meadowsoft]

Don't you mean qubit optimistic?

Re: "More effective teleportation"!?!?!?!

[SpzToid]

640 kbits should be enough for any body.

Re: "More effective teleportation"!?!?!?!

[a_hanso]

640 qubits may or may not be enough for anybody.

Where does extra energy go?

[pclminion]

Suppose I teleport an object from a height of 1000 feet to a height of 0 feet about sea level. There has been a loss of gravitational potential energy -- where does this energy end up? Conversely, if teleporting the object to a higher elevation, how is the gravitational PE imparted to the system?

Re:Where does extra energy go?

[Anonymous Coward]

The name "quantum teleportation" is a bit misleading: no particles, mass or energy is teleported. The only thing "teleported" is a quantum state.

What's remarkable about quantum teleportation is that you can transfer an exact quantum state from one place to another without sending any particle with that state along the way. That's remarkable because quantum states can't, in general, be copied (see the "no-cloning theorem). When you perform a quantum teleportation, you must destroy the state of the originating particle during the teleportation process.

Re:Where does extra energy go?

[NeilJacklin]

Actually, the object does have _potential_ energy. I've wondered about OP's question before. I think the answer has to do with the fact that these "teleporters" don't transport matter in the conventional sense. Suppose you did have have a teleporter that could take an object and teleport it 100 ft up a hill. If you dropped the object, collected the potential energy (like in a waterwheel), and teleported it again, you shouldn't be able to violate conservation of energy or make a perpetual motion machine. So, I figure it's either A) impossible, or B) requires an energy input at _least_ equal to the change in potential energy. \\ Of course, I'm talking about gravitation potential energy, but that's just one field. There's also electromagnetic. Conversely, if it took more energy in than the net change in potential energy, where would that energy go? So I suppose the net energy input should be equal to the change in potential energy. \\ This also raises other issues, like if I teleport very far away, or two a more massive planet, I might need to input a lot of energy on this side. \\ A possible resolution to this problem is that the kind of teleportation here is just informational--that is changing one particle's state to match (or oppose) the one on the other side. Thus no mass (or charge) is transported anywhere, and everything is happy energy-wise.

Re:Where does extra energy go?

[Charliemopps]

Despite the authors attempt to make this sound like it has something to do with teleporting real world objects, it doesn't. Entanglement has to do with 2 particles sharing a state such as spin, and when that state changes in one entangled particle it also changes simultaneously regardless of distance or the speed of light in the other entangled particle. All of the laws of physics are observed. Information can not be passed faster than the speed of light. Matter can not move even at the speed of light, most of it no-where near the speed of light. You can not teleport an object from one place to another at all. There may be extended spacial dimensions that would allow us to do an end-run around distance, but keep in mind, if there are 4 or more spacial dimensions, we and all other matter already exist and are moving in those dimensions. There is very likely physical laws governing travel in them that would have the same effect that normal travel would. For example think if we were 2 dimensional creatures living on the surface of the earth and we suddenly discover the 3rd dimension and realize we could travel through the earth to reach china in half the time. While physically possible, there is that whole "Drilling through thousands of miles of solid rock" obstical that would make it a lot easier to just hop on a jet.

Also, keep in mind that, to my knowledge and I just did a quick check and found nothing, humanity has never entangled anything other than photons/light. Which are technically both a wave and particle, but it's a hell of a long way off from entangling actual normal matter. Let me know when they entangle a Neutron and it'll be a big deal. Don't get me wrong, I think it's not beyond the laws of physics but we are very very very far away from true real world applications. The entanglement of photons can be explained via classical physics/optics, and doesn't need quantum theory to explain the effect. That doesn't mean it's not real, it just means you should take it with a grain of salt.

This discovery makes experimentation easier. Teleporting yourself to work? Not so much.

Re:Where does extra energy go?

[pclminion]

There is one more option, that conservation of energy is not necessarily enforced on quantum level.

Another equally likely option is that at the quantum level everything is made of bacon.

Re:Where does extra energy go?

[stuckinarut]

Humanity has entangled stuff bigger than photons; The Biggest "Spooky" System Ever Seen: 4 Entangled Ions (Jun 2009) and Entangled diamonds , big enough for the eye to see (Dec 2011). We haven't managed the information transportation part with anything other than photons though but we're doing well on distance; quantum key transmitted wirelessly 144km.

Re:The idea of Teleportation

[Esion Modnar]

Is that you, Bones?

Re:The idea of Teleportation

[celle]

"LOL but on Slash, sci-fi is real. Space elevators, warp drives, Mars colonies and the hundreds of attendant magical technologies and fantasy materials are just a question of, like, how hard we really want them to happen."

      And remember Dick Tracy's video wristwatch was described in the 1930s when radio and telephone was less than 50 years old. We have it now and in other forms such as cell phones and tablets less than 75 years later. Slashdot is visited by people in research and science fiction, who knows what could be in the next 100 years if we put the "old nose to the grindstone".

Re:Simple math ...

[MacGyver2210]

Jeff Goldblum says "Thanks, Captain Hindsight!"