Abstract
Quantum information and computation is concerned with the use of quantum-mechanical systems to carry out computational and information-processing tasks [Quantum computation and quantum information]. In the few years that this approach has been studied, a number of remarkable concepts and results have emerged. Our particular focus in this paper is on quantum information protocols, which exploit quantum-mechanical effects in an essential way. The particular examples we shall use to illustrate our approach will be teleportation [Teleporting an unknown quantum state via dual classical and Einstein-Podolsky-Rosen channels], logic-gate teleportation [Quantum teleportation is a universal computational primitive], and entanglement swapping [Event-ready-detectors' Bell experiment via entanglement swapping]. The ideas illustrated in these protocols form the basis for novel and potentially very important applications to secure and fault-tolerant communication and computation.