Quantum Information, 2 Volume Set, 2nd Edition

12 Purification and Distillation

Wolfgang Dür and Hans‐J. Briegel

Institut für Theoretische Physik, Technikerstr. 21A, 6020 Innsbruck, Austria

12.1 Introduction

Entanglement is a unique feature of quantum mechanics that has puzzled physicists since its first discussion by Schrödinger in 1935 (1). For many decades, mainly fundamental issues – such as the relation of entanglement to the existence of local hidden variable models – have been discussed. Only quite recently, questions related to practical aspects of entanglement have emerged. It was realized that entanglement is not only a strange feature of quantum mechanics, but can also be a valuable resource. First applications of entanglement appeared in the context of quantum communication ...