33,500 research outputs found
State Transfer and Spin Measurement
We present a Hamiltonian that can be used for amplifying the signal from a
quantum state, enabling the measurement of a macroscopic observable to
determine the state of a single spin. We prove a general mapping between this
Hamiltonian and an exchange Hamiltonian for arbitrary coupling strengths and
local magnetic fields. This facilitates the use of existing schemes for perfect
state transfer to give perfect amplification. We further prove a link between
the evolution of this fixed Hamiltonian and classical Cellular Automata,
thereby unifying previous approaches to this amplification task.
Finally, we show how to use the new Hamiltonian for perfect state transfer in
the, to date, unique scenario where total spin is not conserved during the
evolution, and demonstrate that this yields a significantly different response
in the presence of decoherence.Comment: 4 pages, 2 figure
Resonance absolute quantum reflection at selected energies
The possibility of the resonance reflection (100 % at maximum) is revealed.
The corresponding exactly solvable models with the controllable numbers of
resonances, their positions and widths are presented.Comment: 5 pages, 2 figure
Self-energy flows in the two-dimensional repulsive Hubbard model
We study the two-dimensional repulsive Hubbard model by functional RG
methods, using our recently proposed channel decomposition of the interaction
vertex. The main technical advance of this work is that we calculate the full
Matsubara frequency dependence of the self-energy and the interaction vertex in
the whole frequency range without simplifying assumptions on its functional
form, and that the effects of the self-energy are fully taken into account in
the equations for the flow of the two-body vertex function. At Van Hove
filling, we find that the Fermi surface deformations remain small at fixed
particle density and have a minor impact on the structure of the interaction
vertex. The frequency dependence of the self-energy, however, turns out to be
important, especially at a transition from ferromagnetism to d-wave
superconductivity. We determine non-Fermi-liquid exponents at this transition
point.Comment: 48 pages, 18 figure
The value of a breast care nurse in supporting rural and remote cancer patients in Queensland
The role of the Breast Care Nurse in Queensland's Supporting Rural Women with Breast Cancer Project was evaluated by mixed methodology. Through questionnaire and interview patients provided views about the nurse's role under categories of Awareness, Access, Coordination, Information and Psychosocial, Emotional and Practical support.
Of the 51 participants 37 resided in rural and remote areas with 18 living between 100 and 500 miles from specialised breast care services. The BCN met with patients at their regular hospital visits and was available by telephone at any time. There was overwhelming agreement among the participants that the timing of contact, ease of accessibility, information provided and support offered were extremely valuable in making their treatment and recovery easier. The vast majority of participants would recommend hospitals with a BCN to their friends.
Members of the multidisciplinary care team provided views on Awareness of the BCN, Influence on Care Management, Communication and Patient Outcomes. They recognised the benefits of the BCN to patients and to coordination and liaison of the team.
The findings concur with unpublished Australian reports that demonstrate the success of dedicated Breast Care Nurses. The BCN model of care could be used successfully to support other medical conditions
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