Exact quantum circuits for measuring entanglement University of Calgary | Presentation | 2005-11-09 | H. Carteret |

Physically accessible non-completely positive mapsThe Kraus representation theorem states that under some plausible assumptions, the most general dynamics that an open quantum system can
undergo is a completely positive map (CP-map). However, one of the assumptions underlying the theorem is a condition on the initial state
of the combined system and environment which is not always satisfied.We will describe the physical reasons why this assumption may not be
true and give a natural definition for when it makes sense to say that a non-CP map is robustly physically realizable (i.e., physically
accessible). We will also discuss what is known about the conditions for a non-CP map to be physically accessible.
University of Calgary | Presentation | 2006-06-09 | H. Carteret |

Noiseless quantum circuits for measuring entanglementI will show how to construct a family of simple circuits that can determine the spectrum of the partial transpose of a density matrix, without modifying the partial transpose map to impose complete positivity. Previous proposed methods for measuring entanglement relied on full state tomography (very inefficient) or the Structural Physical Approximation, which adds large amounts of noise to shift the spectrum of the partially transposed density matrix to be positive, thus incurring a corresponding loss of sensitivity.
My networks depend only on the dimension of the density matrix and do not need any circuit components that are not already required to determine the eigenspectrum of the original density matrix by interferometry. They measure the minimum amount of information required to determine the partial-transpose-spectrum completely and they are exact, up to experimental errors.
University of Calgary | Presentation | 2006-08-08 | H. Carteret |

Quantum random walks with decoherent coins University of Calgary | Publication | 2003-03-01 | T. A. Brun, H. Carteret, A. Ambainis |

On the logical structure of Bell theorems without inequalitites University of Calgary | Publication | 2006-01-01 | A. Broadbent, H. Carteret, A. Méthot, J. Walgate |

Discerning thermal properties of entanglement in qubit rings using n-concurrenceWe show that n-concurrence is an excellent tool for discerning the entanglemnet properties of qubit networks (e.g. rings) and demonstrate multiple entanglement revivals as temperature increses. University of Calgary | Presentation | 2007-06-07 | Y. Sanders, H. Carteret, B. C. Sanders |

Implementing Grover’s quantum search on a para-hydrogen based pure state NMR quantum computer University of Calgary | Publication | 2004-12-01 | M. S. Anwar, D. Blazina, H. Carteret, S. B. Duckett, J. A. Jones |

Preparing high purity initial states for nuclear magnetic resonance quantum computing University of Calgary | Publication | 2004-01-01 | M. S. Anwar, D. Blazina, H. Carteret, S. B. Duckett, T. K. Halstead, J. A. Jones, C. M. Kozak, R. J. Taylor |

Practical implementations of twirl operations University of Calgary | Publication | 2005-03-01 | M. S. Anwar, L. Xiao, A. J. Short, J. A. Jones, D. Blazina, S. B. Duckett, H. Carteret |