Quantum information entanglement

Entanglement is the main resource of quantum information processing, without which quantum computation will not be faster than its classical counterpart [8] and quantum communication protocols will not work [113-115]. Moreover, as shown... 

Efficient theoretical and experimental tools are presented for the control of entanglement in multiatom and multiphoton systems. The problems of storage of quantum information encoded in multiphoton beams and its processing via measurements or controlled interactions with two- and multi-level atomic species are discussed ... 

Role of quantum statistics. When considering complex systems by methods of statistical physics, one operates with their time-dependent distributions. In fermionic systems (see Yu. Ozhigov), statistical requirements imply that we must replace the independent-particle description by a quasiparticle formalism for quantum information processing. Effects of statistical fluctuations on coherent scattering processes (see M. Blaauboer et al.) suggest the need for furher exploration of the role of statistics on the dynamics of entangled systems. 

The concerted discussion of the topics outlined above should help us advance the new paradigm that addresses our abilities to diagnose and manipulate the entangled states of complex quantum objects and their robustness against decoherence. These abilities are required for quantum information (QI) applications or matter-wave interferometry in molecular, semiconducting or superconducting systems. On the fundamental level, this book may help establish the notion of dynamical information exchange between quantum systems and chart in detail the route from unitarity to classicality. 

Abstract I briefly review the status of entanglement in quantum information processing. 

In this article I will discuss entanglement and its role in quantum information processing - especially, but not exclusively in the context of quantum computation. 

I hope I have given you some glimpse into one of the more subtle areas in quantum information processing. Both in terms of some of the progress that we have made in recent years towards understanding when and how entanglement really matters, and in terms of the still open questions. 

Entanglement is a vital information resource employed in quantum teleportation, dense coding and quantum computation [Nielsen 2000], The fundamental role played by the entanglement in quantum information science was discussed in part I this part of the book is devoted to the generation and characterization of the entanglement of photons and their usage in quantum communication and computation protocols. 

We will now present a brief overview of some of the interesting applications in the field of quantum information of our reliable source of distant atomic entanglement. 

One may envision extensions of the present approach to matter teleportation [Opatrny 2001] and quantum computation based on continuous variables [Braunstein 1998 (a) Lloyd 1998 Lloyd 1999], Such extensions may involve the coupling of entangled atomic ensembles in optical lattices by photons carrying quantum information. 

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