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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."
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.
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.