29,679 research outputs found
Entanglement entropy and the determination of an unknown quantum state
An initial unknown quantum state can be determined with a single measurement
apparatus by letting it interact with an auxiliary, "Ancilla", system as
proposed by Allahverdyan, Balian and Nieuwenhuizen [Phys. Rev. Lett. 92, 120402
(2004)]. In the case of two qubits, this procedure allows to reconstruct the
initial state of the qubit of interest S by measuring three commuting
observables and therefore by means of a single apparatus, for the total system
S + A at a later time. The determinant of the matrix of the linear
transformation connecting the measurements of three commuting observables at
time t > 0 to the components of the polarization vector of S at time t = 0 is
used as an indicator of the reconstructability of the initial state of the
system S. We show that a connection between the entanglement entropy of the
total system S + A and such a determinant exists, and that for a pure state a
vanishing entanglement individuates, without a need for any measurement, those
intervals of time for which the reconstruction procedure is least efficient.
This property remains valid for a generic dimension of S. In the case of a
mixed state this connection is lost.Comment: 5 pages 2 figures, accepted for publication on Physical Review
Early childhood nutrition and anaemia prevention project: summary report June 2013
This report summarises and evaluates a program of preventive multi-micronutrient supplementation, peer-counselling and nutrition promotion that was piloted in six remote northern Australian Aboriginal communities.
Introduction
The Early Childhood Nutrition and Anaemia Prevention Project (ECNAPP) was implemented in six remote communities, four in the Northern Territory (NT), one in Cape York in Queensland (Qld) and one in the East Kimberley region in Western Australia (WA). Project planning and development commenced in 2006, with project activities occurring between 2010 and 2012. T
his report summarises the project development, program implementation, results of the evaluation of both project processes and outcomes, and provides recommendations for future policy, programs and research addressing infant and young child nutrition and anaemia in northern Australia.
Authored by Danielle Aquino, Julia V Marley, Kate Senior, Dympna Leonard, Angelina Joshua, Amelia Huddleston, Heather Ferguson, Janet Helmer, Nyssa Hadgraft and Vivienne Hobson
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