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IBM Journal of Research and Development

Issue 1 • Date Jan. 2004

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Displaying Results 1 - 14 of 14
  • Preface

    Publication Year: 2004, Page(s): 3
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (21 KB)

    This issue of the IBM Journal of Research and Development contains papers honoring the life and career of IBM Fellow Charles H. Bennett on the occasion of his sixtieth birthday. Most of the papers are based on talks presented at a symposium held at the IBM Thomas J. Watson Research Center in Yorktown Heights, New York, on May 8 and 9, 2003. Nearly one hundred participants, some from far distant po... View full abstract»

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  • Can complex structures be generically stable in a noisy world?

    Publication Year: 2004, Page(s):5 - 12
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (103 KB)

    Toom's “NEC” cellular automaton is a simple model or dynamical “rule” that succeeds in producing two-phase coexistence generically, i.e., over a nonzero fraction of its two-dimensional parameter space. This paper reviews and explains the behavior of the NEC rule and discusses the implications of the rule for the generic stabilization of complex structures. Much of the d... View full abstract»

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  • A pedestrian's introduction to spacetime crystallography

    Publication Year: 2004, Page(s):13 - 29
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (242 KB)

    Ordinary crystallography deals with regular, discrete, static arrangements in space. Of course, dynamic considerations—and thus the additional dimension of time—must be introduced when one studies the origin of crystals (since they are emergent structures) and their physical properties such as conductivity and compressibility. The space and time of the dynamics in which the crystal i... View full abstract»

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  • Five big questions with pretty simple answers

    Publication Year: 2004, Page(s):31 - 45
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (130 KB)

    Under the roof of one controversial assumption about physics, we discuss five big questions that can be addressed using concepts from a modern understanding of digital informational processes. The assumption is called finite nature. The digital mechanics model is obtained by applying the assumption to physics. The questions are as follows: 1. What is the origin of spin? 2. Why are there symmetries... View full abstract»

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  • The early days of experimental quantum cryptography

    Publication Year: 2004, Page(s):47 - 52
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (951 KB)

    This paper describes the first quantum cryptography experiment, performed at the IBM Thomas J. Watson Research Center in the summer of 1989 by Charles H. Bennett and the author. The apparatus and some of the lesser-known details of the experiment are illustrated and discussed, and quantum cryptography is discussed in the light of some of the more recent research. Also included as an appendix is a ... View full abstract»

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  • Copenhagen computation: How I learned to stop worrying and love Bohr

    Publication Year: 2004, Page(s):53 - 61
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (120 KB)

    To celebrate the 60th birthday of Charles H. Bennett, I 1) publicly announce my referee reports for the original dense coding and teleportation papers, 2) present a very economical solution to the Bernstein–Vazirani problem that does not even hint at interference between multiple universes, and 3) describe how I inadvertently reinvented the Copenhagen interpretation in the course of construct... View full abstract»

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  • What is actually teleported?

    Publication Year: 2004, Page(s):63 - 69
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1432 KB)

    There are no “unknown quantum states.“ The phrase is self-contradictory. Moreover, Alice and Bob are only inanimate objects: They know nothing. What is teleported instantaneously from one system (Alice) to another system (Bob) is the applicability of the preparer's knowledge of the state of a particular qubit in the systems. The operation necessitates the use of dual classical and qu... View full abstract»

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  • Is entanglement monogamous?

    Publication Year: 2004, Page(s):71 - 78
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (2579 KB)

    In this paper I discuss some of the early history of quantum information theory. By considering the question of whether entanglement is “monogamous,” I illustrate Charles Bennett's influence on modern quantum information theory. Finally, I review our recent answers to this entanglement question and its relation to Bell inequalities. View full abstract»

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  • Illustrating the concept of quantum information

    Publication Year: 2004, Page(s):79 - 85
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (92 KB)

    Over the past decade, quantum information theory has developed into a vigorous field of research despite the fact that quantum information, as a precise concept, is undefined. Indeed, the very idea of viewing quantum states as carriers of some kind of information (albeit unknowable in classical terms) leads naturally to interesting questions that might otherwise never have been asked, and correspo... View full abstract»

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  • TelePOVM—A generalized quantum teleportation scheme

    Publication Year: 2004, Page(s):87 - 97
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (123 KB)

    In this paper, we show that quantum teleportation is a special case of a generalized Einstein-Podolsky-Rosen (EPR) nonlocality. On the basis of the connection between teleportation and generalized measurements, we define conclusive teleportation. We show that perfect conclusive teleportation can be obtained with any pure entangled state, and it can be arbitrarily approached with a particular mixed... View full abstract»

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  • Picturing qubits in phase space

    Publication Year: 2004, Page(s):99 - 110
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (140 KB)

    Focusing particularly on one-qubit and two-qubit systems, I explain how the quantum state of a system of n qubits can be expressed as a real function—a generalized Wigner function—on a discrete 2n × 2n phase pace. The phase space is based on the finite field having 2n elements, and its geometric structure leads naturally to the construction of ... View full abstract»

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  • Some bipartite states do not arise from channels

    Publication Year: 2004, Page(s):111 - 114
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (82 KB)

    It is well known that the action of a quantum channel on a state can be represented, using an auxiliary space, as the partial trace of an associated bipartite state. Recently, it was observed that for the bipartite state associated with the optimal average input of the channel, the entanglement of formation is simply the entropy of the reduced density matrix minus the Holevo capacity. It is natura... View full abstract»

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  • The adaptive classical capacity of a quantum channel, or Information capacities of three symmetric pure states in three dimensions

    Publication Year: 2004, Page(s):115 - 137
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1792 KB)

    We investigate the capacity of three symmetric quantum states in three real dimensions to carry classical information. Several such capacities have already been defined, depending on what operations are allowed in the protocols that the sender uses to encode classical information into these quantum states, and that the receiver uses to decode it. These include the C1,1 capacity, which i... View full abstract»

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  • Quantum information isomorphism: Beyond the dilemma of the Scylla of ontology and the Charybdis of instrumentalism

    Publication Year: 2004, Page(s):139 - 147
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (101 KB)

    In order to deal most effectively with the unanalyzable quantum whole, the Copenhagen interpretation takes as a “frame of reference” the preparation parameters and outcomes of measurements. It represents a passive, Ptolemaic-like instrumentalism directly related to “what we see in the sky,” i.e., to the “surface” of reality. However, the notion of quantum ... View full abstract»

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Aims & Scope

The IBM Journal of Research and Development is a peer-reviewed technical journal, published bimonthly, which features the work of authors in the science, technology and engineering of information systems.

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Editor-in-Chief
Clifford A. Pickover
IBM T. J. Watson Research Center