Entanglement: Mystery and Resource

Abstract

Entanglement represents one of the basic features of quantum theory, which has for a long time been described as “mysterious” and “potentially paradoxical”. Although the term “entanglement” was not explicitly used by Einstein, Podolsky and Rosen in their celebrated article “Can quantum mechanical description of reality be considered complete?”, entangled pure states are essentially involved in the paradoxical situation discussed in their paper. Chapter 3 is devoted to a logical analysis of the Einstein-Podolsky-Rosen paradox (in jargon “EPR-paradox”). It is shown how “EPR-situations” have later on been transformed into powerful resources, even from a technological point of view. As a significant example, teleportation-experiments are briefly illustrated.