quantum mechanics - Could teleportation ever really happen?

Could any form of matter teleportation every really happen?

If so, what form would it take? Some science-fiction talks about literally sending the atoms from one location to another; others talk of creating a duplicate and destroying the original.

Question originally added here.

Update: there are a couple of comments asking me to specify what I mean by teleportation. I'm talking about stuff of Star Trek - taking an object or person and transporting them almost instantly across great distances (thousands of KMs) by:

1. breaking them up at the atomic (or smaller) level


2. transporting those atomic components (or the information, "recipe" to recreate) and


3. (re-)assembling at the new location.

Answer

I don't think it's possible in the way you mean it:

Option 1

Decompose, move, rebuild

Decomposition is possible as long as we can consider the matter classical. If any quantum state is relevant, it will be automatically destroyed in the process of measuring the state of each atom in order to be able to rebuild later. This will lead to a large increase in entropy (which is relevant in the last step).

The movement of a stream of atoms is possible, but not simple at all, especially if you need to focus it in a spot. The energy required, though is probably very similar to the energy required to transport the matter classically.

Rebuilding is possible (given enough technology, that is), but it would be enormously expensive in terms of energy because of the need of reversing the increase of entropy in the first step, locally.

All in all, it's probably possible, but much more expensive in terms of energy than simply moving the body, so it's not clear to me how useful it would be.

Also, were the matter being transported a living being, there are a number of ethical questions involved: would the person rebuilt be still the same person as the one killed by the first step of the process?

Option 2

Use quantum teleportation

This, as far as I know, requires a quantum entanglement between the mass and a perfect copy of the mass. Although this is probably possible for simple systems, I am not really sure it represents the kind of teleportation you are looking for. It's a teleportation of quantum states, not of matter.

Option 3

Abuse Quantum Mechanics

This is far off, and there's nothing suggesting that it's possible, but if we found a way of interfering radically with the probabilities of quantum mechanical measurements, we could leverage the indeterminacy in the body's position to make it move. It really depends on us understanding better how the wave function actually collapses.

Option 4

Abuse General Relativity

This is also far off, but if we were to open a stable wormhole between two positions then it should be possible to step from one place to another instantly. This merely requires using currently unknown forms of exotic matter to generate the holes, because all the wormholes that we know of, in GR, are actually of really small diameter and also apparently a not very healthy place to be because of extreme gravity, radiation and so on.

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A couple of good resources (divulgative but physically accurate):

Physics of the Impossible: A Scientific Exploration of the World of Phasers, Force Fields, Teleportation and Time Travel

The Physics of Star Trek