Quantum teleportation and entanglement swapping viewed from different moving frames

Abstract

It is shown that quantum teleportation and entanglement swapping can be easily derived from Einstein, Podolsky and Rosen correlations and special relativity (SR). A recent proposal of entanglement swapping via delayed-choice experiment is discussed by means of a concrete example. Experiments in decoherence in high-Q cavities are briefly examined from the point of view of SR. It is argued that although decoherence can explain why we never see a Schrödinger ‘cat’ which is dead and alive at the same time, this approach apparently does little to explain the cat's ‘real’ state.