J. A. Jones

Publications (6)2.14 Total impact

• Source

  Available from: arxiv.org

  Article: Tackling Systematic Errors in Quantum Logic Gates with Composite Rotations

  H. K. Cummins, G. Llewellyn, J. A. Jones
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  ABSTRACT: We describe the use of composite rotations to combat systematic errors in single qubit quantum logic gates and discuss three families of composite rotations which can be used to correct off-resonance and pulse length errors. Although developed and described within the context of NMR quantum computing these sequences should be applicable to any implementation of quantum computation.
  09/2002;
• Source

  Available from: arxiv.org

  Article: Approximate Quantum Cloning with Nuclear Magnetic Resonance

  H. K. Cummins, C. Jones, A. Furze, N. F. Soffe, M. Mosca, J. M. Peach, J. A. Jones
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  ABSTRACT: Here we describe a Nuclear Magnetic Resonance (NMR) experiment that uses a three qubit NMR device to implement the one to two approximate quantum cloning network of Buzek et al.
  12/2001;
• Article: Resonance offset tailored composite pulses.

  H K Cummins, J A Jones
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  ABSTRACT: We describe novel composite pulse sequences which act as general rotors and thus are particularly suitable for nuclear magnetic resonance quantum computation. The resonance offset tailoring to enhance nutations approach permits perfect compensation of off-resonance errors at two selected frequencies placed symmetrically around the frequency of the radiofrequency source.
  Journal of Magnetic Resonance 03/2001; 148(2):338-42. · 2.14 Impact Factor
• Source

  Available from: arxiv.org

  Article: Resonance Offset Tailored Pulses for NMR Quantum Computation

  H. K. Cummins, J. A. Jones
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  ABSTRACT: We describe novel composite pulse sequences which act as general rotors and thus are suitable for nuclear magnetic resonance (NMR) quantum computation. The Resonance Offset Tailoring To Enhance Nutations (ROTTEN) approach permits perfect compensation of off-resonance errors at two selected frequencies placed symmetrically around the frequency of the RF source.
  09/2000;
• Source

  Available from: ox.ac.uk

  Article: Nuclear magnetic resonance: a quantum technology for computation and spectroscopy

  H K Cummins, J A Jones
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  ABSTRACT: In this article we consider nuclear magnetic resonance (NMR) as an example of a quantum technology; we consider in particular de-tail the implementation of quantum computers using NMR. We begin by outlining the physical principles underlying NMR, and give an in-troduction to the quantum mechanics involved. We next discuss the general characteristics of quantum technologies and the ways and ex-tent to which these characteristics are expressed in NMR. We then give an introduction to the subject of quantum computation and its implementation using NMR. Finally, we describe some spectroscopy techniques which also exploit the quantum nature of NMR.
  09/2000;
• Source

  Available from: arxiv.org

  Article: Use of composite rotations to correct systematic errors in NMR quantum computation

  H. K. Cummins, J. A. Jones
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  ABSTRACT: We implement an ensemble quantum counting algorithm on three NMR spectrometers with 1H resonance frequencies of 500, 600 and 750 MHz. At higher frequencies, the results deviate markedly from naive theoretical predictions. These systematic errors can be attributed almost entirely to off-resonance effects, which can be substantially corrected for using fully-compensating composite rotation pulse sequences originally developed by Tycko. We also derive an analytic expression for generating such sequences with arbitrary rotation angles. Comment: 8 pages RevTex including 7 PostScript figures (18 subfigures)
  11/1999;