33 research outputs found

    Extremely long quasiparticle spin lifetimes in superconducting aluminium using MgO tunnel spin injectors

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    There has been an intense search in recent years for long-lived spin-polarized carriers for spintronic and quantum-computing devices. Here we report that spin polarized quasi-particles in superconducting aluminum layers have surprisingly long spin-lifetimes, nearly a million times longer than in their normal state. The lifetime is determined from the suppression of the aluminum's superconductivity resulting from the accumulation of spin polarized carriers in the aluminum layer using tunnel spin injectors. A Hanle effect, observed in the presence of small in-plane orthogonal fields, is shown to be quantitatively consistent with the presence of long-lived spin polarized quasi-particles. Our experiments show that the superconducting state can be significantly modified by small electric currents, much smaller than the critical current, which is potentially useful for devices involving superconducting qubits

    Partnership, ownership and control: the impact of corporate governance on employment relations

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    Prevailing patterns of dispersed share ownership and rules of corporate governance for UK listed companies appear to constrain the ability of managers to make credible, long-term commitments to employees of the kind needed to foster effective labour-management partnerships. We present case study evidence which suggests that such partnerships can nevertheless emerge where product market conditions and the regulatory environment favour a stakeholder orientation. Proactive and mature partnerships may also be sustained where the board takes a strategic approach to mediating between the claims of different stakeholder groups, institutional investors are prepared to take a long-term view of their holdings, and strong and independent trade unions are in a position to facilitate organisational change

    Open borders in the nineteenth century : constructing the national, the citizen and the foreigner in South America

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    This working paper describes and explains the historical origins of the division between the national and the foreigner in South America. In the early nineteenth century, all the previously Spanish possessions in South America as well as Brazil achieved independence. With this new freedom, countries turned their attention to asserting their statehood through the delineation of three constitutive elements: government, territory and population. The new governments had to define who were going to be considered as nationals, citizens and foreigners, and the rights that pertained to each of these categories. These countries were all concerned with attracting new settlers and very early on introduced constitutional provisions on open borders and equal treatment for foreigners. White, male Europeans were the principal addresses of open borders provisions in an effort to entice them to settle in territories presented as empty to the exclusion of indigenous groups, bring new industries, and contribute to the whitening of mixed race populations. Whilst weak statehood came with independence, forming nations was a much longer process and States used migration and citizenship policies as tools to define nationhood
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