2,054 research outputs found
Everett and the Born Rule
During the last ten years or so, derivations of the Born rule based on
decision theory have been proposed and developed, and it is claimed that these
are valid in the context of the Everett interpretation. This claim is
critically assessed and it is shown that one of its key assumptions, although
natural in the context of the Copenhagen interpretation, is not consistent with
that of Everett. It is further argued that any interpretation that relates
outcome likelihood to the expansion coefficients connecting the wavefunction
with the eigenfunctions of the measurement operator must be inconsistent with
the Everett interpretation.Comment: 22 pages 1 figur
All-optical non-demolition measurement of single-hole spin in a quantum-dot molecule
We propose an all-optical scheme to perform a non-demolition measurement of a
single hole spin localized in a quantum-dot molecule. The latter is embedded in
a microcavity and driven by two lasers. This allows to induce Raman transitions
which entangle the spin state with the polarization of the emitted photons. We
find that the measurement can be completed with high fidelity on a timescale of
100 ps, shorter than the typical T2. Furthermore, we show that the scheme can
be used to induce and observe spin oscillations without the need of
time-dependent magnetic fields
Vaccines – but not as we know them: An ethical evaluation of HPV vaccination policy in Australia
Objective: To show how systematic ethical evaluation of public health policy may reveal issues of moral significance for critical examination. Method: Using Australia's human papillomavirus (HPV) vaccination program as an exemplar and adopting an approach outlined elsewhere, we determine whether conditions of effectiveness, proportionality, necessity and least infringement, and public justification, are met such that any breach of autonomy or justice principles associated with this intervention can be defended. Conclusions: While the HPV vaccine itself may be efficacious, some aspects of the program lack sufficient moral justification and raise concerns around procedural and social justice and gender equity. Implications: Public health interventions deploying new technologies against new targets – such as vaccines against cancer and chronic illness – require approaches crafted to their specific risk-benefit profiles that have carefully considered the ethical issues involved. Systematic ethical reflection is a useful tool for this
Nonlinear nanomechanical resonators for quantum optoelectromechanics
We present a scheme for tuning and controlling nano mechanical resonators by
subjecting them to electrostatic gradient fields, provided by nearby tip
electrodes. We show that this approach enables access to a novel regime of
optomechanics, where the intrinsic nonlinearity of the nanoresonator can be
explored. In this regime, one or several laser driven cavity modes coupled to
the nanoresonator and suitably adjusted gradient fields allow to control the
motional state of the nanoresonator at the single phonon level. Some
applications of this platform have been presented previously [New J. Phys. 14,
023042 (2012), Phys. Rev. Lett. 110, 120503 (2013)]. Here, we provide a
detailed description of the corresponding setup and its optomechanical coupling
mechanisms, together with an in-depth analysis of possible sources of damping
or decoherence and a discussion of the readout of the nanoresonator state.Comment: 15 pages, 6 figure
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Developing professionalism in new IT graduates? Who needs it?
A new graduate may require a period of ‘acclimatisation’ through a process of ‘developing their professionalism’ to fit into their work environment. The e-Skills UK Technology Counts Insights 2010 report suggests that 110,500 new entrants a year are required to fill IT & Telecoms professional job roles, with 20,800 coming from education (predominantly graduate level and higher). However, 43% of recruiters were reporting a lack of suitable candidates for IT & Telecoms posts where growing importance will be placed on relationship management, business process analysis and design, project and programme management. IT & Telecoms professionals are increasingly expected to be multi-skilled, with sophisticated business and interpersonal skills as well as technical competence. As the report also says: ‘UK growth will continue to be primarily in high-value roles with an increasing need for customer and business-oriented skills as well as sophisticated technical competencies.’
The diverse needs and requirements of the IT sector, as specified by various employer groups and professional bodies including BCS, IET, eSkills, the CBI and the SFIA Foundation, are discussed. According to the CBI, ‘62% of entrants to the IT sector need to draw on managerial and professional business skills almost immediately.’ For organisations to succeed, their IT graduate recruits must supplement their IT skills with managerial and professional business skills. Well considered CPD will ensure that recent graduates can enhance their ‘academic’ skills with the necessary work-based skills for the benefit of both themselves and their new employer. The focus of the improvement will balance the student-centred needs for development and the engaging employer’s commercial needs
Failure of the Standard Coupled-Channels Method in Describing the Inelastic Reaction Data: On the Use of a New Shape for the Coupling Potential
We present the failure of the standard coupled-channels method in explaining
the inelastic scattering together with other observables such as elastic
scattering, excitation function and fusion data. We use both microscopic
double-folding and phenomenological deep potentials with shallow imaginary
components. We argue that the solution of the problems for the inelastic
scattering data is not related to the central nuclear potential, but to the
coupling potential between excited states. We present that these problems can
be addressed in a systematic way by using a different shape for the coupling
potential instead of the usual one based on Taylor expansion.Comment: 10 pages, 4 figures, 1 table, Latex:RevTex4 published in J. Phys. G:
Nucl. Part. Phy
First Order Premelting Transition of Vortex Lattices
Vortex lattices in the high temperature superconductors undergo a first order
phase transition which has thus far been regarded as melting from a solid to a
liquid. We point out an alternative possibility of a two step process in which
there is a first order transition from an ordinary vortex lattice to a soft
vortex solid followed by another first order melting transition from the soft
vortex solid to a vortex liquid. We focus on the first step. This premelting
transition is induced by vacancy and interstitial vortex lines. We obtain good
agreement with the experimental transition temperature versus field, latent
heat, and magnetization jumps for YBCO and BSCCO.Comment: revised version replaces 9705092, 5 pages, Latex, 2 postscript
figures, defect line wandering is included, 2 step melting is propose
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