2,962 research outputs found

    Anti-chiral edge states in an exciton polariton strip

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    We present a scheme to obtain anti-chiral edge states in an exciton-polariton honeycomb lattice with strip geometry, where the modes corresponding to both edges propagate in the same direction. Under resonant pumping the effect of a polariton condensate with nonzero velocity in one linear polarization is predicted to tilt the dispersion of polaritons in the other, which results in an energy shift between two Dirac cones and the otherwise flat edge states become tilted. Our simulations show that due to the spatial separation from the bulk modes the edge modes are robust against disorder.Comment: 6 pages, 5 figure

    Magnetic Field Control of the Optical Spin Hall Effect

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    We investigate theoretically the effect of an external magnetic field on polarization patterns appearing in quantum microcavities due to the optical spin Hall effect (OSHE). We show that increase of the magnetic field perpendicular to the plane of the cavity resulting in the increase of the Zeeman splitting leads to the transition from azimuthal separation of polarizations to their radial separation. This effect can be straightforwardly detected experimentally.Comment: 9 pages, 6 figure

    Device independent state estimation based on Bell's inequalities

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    The only information available about an alleged source of entangled quantum states is the amount SS by which the Clauser-Horne-Shimony-Holt (CHSH) inequality is violated: nothing is known about the nature of the system or the measurements that are performed. We discuss how the quality of the source can be assessed in this black-box scenario, as compared to an ideal source that would produce maximally entangled states (more precisely, any state for which S=22S=2\sqrt{2}). To this end, we introduce several inequivalent notions of fidelity, each one related to the use one can make of the source after having assessed it; and we derive quantitative bounds for each of them in terms of the violation SS. We also derive a lower bound on the entanglement of the source as a function of SS only.Comment: 8 pages, 2 figures. Added appendices containing proof

    The Design for a Nanoscale Single-Photon Spin Splitter

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    We propose using the effective spin-orbit interaction of light in Bragg-modulated cylindrical waveguides for the effcient separation of spin-up and spin-down photons emitted by a single photon emitter. Due to the spin and directional dependence of photonic stopbands in the waveguides, spin-up (down) photon propagation in the negative (positive) direction along the waveguide axis is blocked while the same photon freely propagates in the opposite direction.Comment: 5 pages, 3 figure

    Current Issues in Health Technology Assessment of Cancer Therapies: A Survey of Stakeholders and Opinion Leaders in Australia.

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    OBJECTIVE: The aim of this study was to find ways of bridging the gap in opinions concerning health technology assessment (HTA) in reimbursement submission between manufacturers and payers to avoid access delays for patients of vital medicines such as oncology drugs. This was done by investigating differences and similarities of opinion among key stakeholders in Australia. METHODS: The survey comprised of nine sections: background demographics, general statements on HTA, clinical claim, extrapolations, quality of life, costs and health resource utilization, agreements, decision making, and capability/capacity. Responses to each question were summarized using descriptive statistics and comparisons were made using chi-square statistics. RESULTS: There were ninety-seven respondents in total, thirty-seven from the public sector (academia/government) and sixty from the private sector (industry/consultancies). Private and public sector respondents had similar views on clinical claims. They were divided when it came to extrapolation of survival data and costs and health resource utilization. However, they generally agreed that rebates are useful, outcomes-based agreements are difficult to implement, managed entry schemes are required when data are limited, and willingness to pay is higher in cancer compared to other therapeutic areas. They also agreed that training mostly takes place through on the job training and that guideline updates were a least favored opportunity for continued training. CONCLUSIONS: Private sector respondents favor methods that reduce the incremental cost-effectiveness ratio when compared to the public sector respondents. There still exist a number of challenges for HTA in oncology and many research opportunities as a result of this study

    Reassessing the cost-effectiveness of Nivolumab for the treatment of renal cell carcinoma based on mature survival data, updated safety and lower comparator price.

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    Aims: The aim of this study was to estimate the cost-effectiveness of nivolumab versus everolimus for second-line treatment of renal cell carcinoma (RCC) based on mature data, updated safety and decreased everolimus price. Materials and methods: A 3-state (pre-progression/progression-free disease, progressive disease and death) Markov model was developed from the perspective of the Australian health care system. Two scenarios were tested. Scenario 1 used 30-months clinical data and scenario 2 used updated 80-months clinical data with updated everolimus price. Inputs for quality-of-life and costs were informed by the literature and government sources. Incremental cost-effectiveness ratio (ICER) per quality adjusted life years (QALY) gained was reported and an ICER threshold of AU75,000wasassumed.Thresholdanalysiswasperformed,anduncertaintywasexploredusingonewayandprobabilisticsensitivityanalyses.Results:Inscenario1,themodelestimated1.73QALYsatacostofAU75,000 was assumed. Threshold analysis was performed, and uncertainty was explored using one-way and probabilistic sensitivity analyses. Results: In scenario 1, the model estimated 1.73 QALYs at a cost of AU105,000 for nivolumab and 1.48 QALYs at AU38,000foreverolimuswithanICER=AU38,000 for everolimus with an ICER = AU266,871/QALY gained. A rebate of 54.4% was needed for nivolumab to reach the ICER threshold. For scenario 2, 1.93 QALYs at AU111,418wasestimatedfornivolumaband1.60QALYsatAU111,418 was estimated for nivolumab and 1.60 QALYs at AU31,942 for everolimus with an ICER of AU$213,320/QALY gained. The rebate needed to reach the ICER threshold was 54.9%. One-way sensitivity analyses for both scenarios showed that the cost of nivolumab, time horizon and utilities were main drivers. The cost-effectiveness acceptability curves highlighted the differences in cost-effectiveness of the two scenarios, as well as significant uncertainty in the results. Conclusions: A 54% rebate of the published price is needed for nivolumab to be cost-effective in Australia for the treatment of RCC. At that rebate, nivolumab remains cost-effective despite severe price erosion of everolimus because of improved longer term follow-up data. We recommend that generic price erosion should be accounted for when performing cost-effectiveness analysis

    Operation speed of polariton condensate switches gated by excitons

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    We present a time-resolved photoluminescence (PL) study in real- and momentum-space of a polariton condensate switch in a quasi-1D semiconductor microcavity. The polariton flow across the ridge is gated by excitons inducing a barrier potential due to repulsive interactions. A study of the device operation dependence on the power of the pulsed gate beam obtains a satisfactory compromise for the ON/OFF-signal ratio and -switching time of the order of 0.3 and 50\thicksim50 ps, respectively. The opposite transition is governed by the long-lived gate excitons, consequently the OFF/ON-switching time is 200\thicksim200 ps, limiting the overall operation speed of the device to 3\thicksim3 GHz. The experimental results are compared to numerical simulations based on a generalized Gross-Pitaevskii equation, taking into account incoherent pumping, decay and energy relaxation within the condensate.Comment: 11 pages, 11 figure

    Polariton Condensate Transistor Switch

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    A polariton condensate transistor switch is realized through optical excitation of a microcavity ridge with two beams. The ballistically ejected polaritons from a condensate formed at the source are gated using the 20 times weaker second beam to switch on and off the flux of polaritons. In the absence of the gate beam the small built-in detuning creates potential landscape in which ejected polaritons are channelled toward the end of the ridge where they condense. The low loss photon-like propagation combined with strong nonlinearities associated with their excitonic component makes polariton based transistors particularly attractive for the implementation of all-optical integrated circuits
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