They also discussed several different means to read out the result. This system still dealt with relatively few qubits, but magnetic resonance methods would make much more robust QCs. Again, a very recent paper by R Laflamme and others, using many ideas from the physics literature, discusses error correction in QCs. They add 2 extra qubits to signal the presence of an error. The novelty in their paper is its estimate of the maximum size of error with which a QC can cope.
Total error is calculated when the result is read out.
This, too, helps make QCs look much more possible. Figure 1 shows a simplified version of their setup for Alice to send an untouched quantum signal to Bob, teleporting it, in a sense. This diagram gives a simplified version of the setup for sending a photon by quantum teleportation. A is Alice and B is Bob. She sends the normal message to B, telling him what she did.