14,277 research outputs found

    Non-Abelian Majorana modes protected by an emergent second Chern number

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    The search for topological superconductors and non-Abelian Majorana modes ranks among the most fascinating topics in condensed matter physics. There now exist several fundamental superconducting phases which host symmetry protected or chiral Majorana modes. The latter, namely the chiral Majorana modes are protected by Chern numbers in even dimensions. Here we propose to observe novel chiral Majorana modes by realizing Fulde-Ferrell-Larkin-Ovchinnikov state, i.e. the pairing density wave (PDW) phase in a Weyl semimetal which breaks time-reversal symmetry. Without symmetry protection, the 3D gapped PDW phase is topologically trivial. However, a vortex line generated in such phase can host chiral Majorana modes, which are shown to be protected by an emergent second Chern number of a synthetic 4D space generalized from the PDW phase. We further show that these chiral modes in the vortex rings obey 3D non-Abelian loop-braiding statistics, which can be applied to topological quantum computation.Comment: 5 pages + supplementary matrial. Reference and some discussions are update

    Factors contributing to successful public private partnership projects - Comparing Hong Kong with Australia and the United Kingdom

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    Purpose: With the increasing interest in Public Private Partnership (PPP) there is a need to investigate the factors contributing to successful delivery of PPP projects. Design/methodology/approach: An empirical questionnaire survey was conducted in Hong Kong and Australia. The survey respondents were asked to rate eighteen factors which contribute to delivering successful PPP projects. Findings: The findings from this survey were further compared with the results achieved by a previous researcher (Li, 2003) in a similar survey conducted in the United Kingdom. The comparison showed that amongst the top five success factors ranked by Hong Kong respondents, three were also ranked highly by the Australians and British. These success factors included: ‘Commitment and responsibility of public and private sectors’; ‘Strong and good private consortium’; and ‘Appropriate risk allocation and risk sharing’. Originality/value: These success factors were therefore found to be important for contributing to successful PPP projects irrespective of geographical locations

    Regional analysis on the implementation of Madrid International Plan on ageing

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    The world’s population is rapidly ageing, are countries all geared up to withstand the impacts brought by the demograph­ical changes? 2002 marked an historical moment for the ageing world, where the Madrid International Plan of Action on Ageing (hereafter ‘MIPAA’) was adopted by 159 countries worldwide at the Second World Assembly on Ageing held in Spain. Countries pledged their commitments to building a society for all ages by means of institutional arrangement, poli­cies and programmes. The document sets out objectives and priority areas in dealing with the ageing population, which serve as guiding principles to policymakers and service providers. 10 years since MIPAA was adopted in 2002, how much progresses countries have made since then? How far countries are from the goals established in 2002? The paper will provide a detailed account the progress on the implementation of MIPAA in regard to ageing policies and programmes based on the responses from 30 countries and areas s in Asia and Pacific region under three priority directions (1) Older Persons and Development; (2) Advancing Health into Old Age; and (3) Ensuring Enabling and Supportive Environments . 「马德里国际老龄问题国际行动计划地域性分析」 摘要 全球人口急速老化,世界各国是否已为人口结构转变而来的挑战做好应对的准备?2002年是历史性的一年,全球159个国家于第二次老龄问题世界大会签订《马德里老龄问题国际行动计划》(下称《行动计划》),承诺以政策及服务建构全龄社会。《行动计划》勾划了国家应对人口老化的政策目标与服务方略,为政策制定者及服务提供者提供指导性原则。从2002年起转眼十年,世界各国进展如何?距离2002年订定的目标还有多远?本论文将就亚太地区30个国家就《行动计划》的三大优先方向:(1)老年人与发展、(2)增进老年人的健康和福祉及 (3)确保老年人有利的支助性环境所实施的老龄政策与项目探讨《行动计划》的落实情况

    Influence of electron scatterings on thermoelectric effect

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    In this work, we employed non-equilibrium Green's function to investigate the electron transport properties in the nanowire with the presence of scatterings. The scattering mechanism is modelled by using the concept of B\"uttiker probe. The effect of electron scattering is analyzed under three conditions: absence of external field; with a bias voltage; and with a finite temperature difference. It is found weak and strong scatterings strength affect the electron transport in different ways. In the case of weak scattering strength, electron trapping increase the electron density, hereafter boost the conductance significantly. Although the increment in conductance would reduce the Seebeck coefficient slightly, the power factor still increases. In the case of strong scattering strength, electron diffraction causes the redistribution of electrons, accumulation of electron at the ends of the wire blocks current flow; hence the conductance is reduced significantly. Although the Seebeck coefficient increases slightly, the power factor still decreases. The power factor is enhanced by 6%-18%, at the optimum scattering strength

    Understanding adoption and continual usage behaviour towards internet banking services in Hong Kong

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    Banks and financial institutions in Hong Kong are increasingly finding themselves facing rapid increases in turbulence and complexity, leading to greater uncertainty and increased competition. Customers are also becoming more demanding. Apart from the traditional type of banking services, customers today require more personalized products and services, and access to such services at any time, and at any place. Although there is no panacea for banks to stay competitive, Internet Banking is one of the advanced information technologies they can employ to achieve a high level of customer services. Internet Banking is an emerging technology that permits conduct of banking transactions through the Internet. From the banks’ point of view, it requires the lowest transaction cost among various channels, just one percent of branch-based banking. It also can improve the efficiency and effectiveness of corporate business processes through elimination of paper work. One of the many benefits of Internet Banking is that customers can use bank services 24 hours a day from anywhere in the world. This study investigates university students\u27 adoption/continual usage behaviour within the context of Hong Kong Internet Banking services. A research framework based on the extension of Technology Acceptance Model and Social Cognitive Theory was developed to identify factors that would influence the adoption/continual usage of Internet Banking. The framework includes subjective norm, image, result demonstrability, perceived risk, computer self-efficacy, perceived usefulness, perceived ease of use and intention constructs. A diverse sample of undergraduate and postgraduate students of seven universities in Hong Kong was used to test the models. Structural Equation Modeling was used to examine the entire pattern of intercorrelations among the eight proposed constructs and to test related propositions empirically. The results reveal that both subjective norm and computer self-efficacy play significant roles in influencing the intention to adopt Internet Banking indirectly. Perceived usefulness has significant positive effect on intention to adopt, this result supports the extension of the Technology Acceptance Model. Perceived ease of use has significant indirect effect on intention to adopt/continual usage through perceived usefulness, while its direct effect on intention to adopt is not significant in this empirical study. Theoretical contributions and practical implications of the findings are discussed and suggestions for future research are presented