3 ms·
People call it teleportation because it moves the state of a system from one place to another, without going through the intermediate positions. I'm not sure w
by greeneggs 14y ago
People call it teleportation because it moves the state of a system from one place to another, without going through the intermediate positions. I'm not sure where this idea came from that teleportation has to be "instantaneous." From special relativity, we know that the word "instantaneous" isn't even well-defined, except in a fixed reference frame.
Basically, quantum teleportation takes the quantum state of a system, measures it. The measurement destroys the system and converts it into classical information that can be sent over a phone line. The information, once received, can be used to reconstruct the initial state.
If you think of a classical system, as computer scientists usually do, this is not very surprising. It seems obvious that in principle you could look very carefully at a complicated classical system, a human being for example, write down all of its details down to the positions of the individual atoms as a long classical string, and send this information down a phone line to reconstruct the person at the other end. It is only surprising because quantum teleportation works with quantum systems, and we know that there is no physical way of extracting all the details of a quantum system as a long classical string (Heisenberg's uncertainty principle, etc.).