19,824 research outputs found

    Implications of Lorentz covariance for the guidance equation in two-slit quantum interference

    Full text link
    It is known that Lorentz covariance fixes uniquely the current and the associated guidance law in the trajectory interpretation of quantum mechanics for spin particles. In the non-relativistic domain this implies a guidance law for the electron which differs by an additional spin-dependent term from that originally proposed by de Broglie and Bohm. In this paper we explore some of the implications of the modified guidance law. We bring out a property of mutual dependence in the particle coordinates that arises in product states, and show that the quantum potential has scalar and vector components which implies the particle is subject to a Lorentz-like force. The conditions for the classical limit and the limit of negligible spin are given, and the empirical sufficiency of the model is demonstrated. We then present a series of calculations of the trajectories based on two-dimensional Gaussian wave packets which illustrate how the additional spin-dependent term plays a significant role in structuring both the individual trajectories and the ensemble. The single packet corresponds to quantum inertial motion. The distinct features encountered when the wavefunction is a product or a superposition are explored, and the trajectories that model the two-slit experiment are given. The latter paths exhibit several new characteristics compared with the original de Broglie-Bohm ones, such as crossing of the axis of symmetry.Comment: 27 pages including 6 pages of figure

    Entangled-state cryptographic protocol that remains secure even if nonlocal hidden variables exist and can be measured with arbitrary precision

    Full text link
    Standard quantum cryptographic protocols are not secure if one assumes that nonlocal hidden variables exist and can be measured with arbitrary precision. The security can be restored if one of the communicating parties randomly switches between two standard protocols.Comment: Shortened version, accepted in Phys. Rev.

    Shaping the future for primary care education and training project. Best practise in education and training strategies for integrated health and social care: development of a benchmarking tool

    Get PDF
    Collaboration and partnership working between Higher Education and the NHS is an essential requirement for effective delivery of care (Universities UK 2003). The North West Universities Association (NWUA) and the North West Development Agency (NWDA) are two organisations at the forefront of creating such alliances. The research project, Shaping the Future for Primary Care Education and Training Project is a collaborative partnership between both these organisations and seven North West Higher Education Institutions. In addition, the project brings together for the first time all the key partners in the health, social care and education sectors who are involved in supporting the delivery of integrated health and social care in the North West Region

    Transitions and progress: teachers' views of progress in attainment of pupils age 5-10

    Get PDF
    There has been a longstanding concern in England and Wales with the year on year progress made by pupils, but particularly at times of change, such as transfer from primary to secondary school at age 11. In Coalton, a former mining town in the North of England, a five year UK government funded initiative known as Charter for Transition has been put in place to try to overcome some of these difficulties and improve the learning opportunities for pupils aged 5-16. The programme takes place over a 5-year period in various stages, but in this paper we make use of data from the first two years. The research team examines the viewpoints of teachers from schools that were receiving additional support in their efforts to raise achievement in phase one and the pilot phase of the project about what they saw as the main benefits of this work. We present the beginnings of our exploration of teachers’ judgements of this work, and what they saw as the difficulties with associating the project with pupil attainment.</p
    • …
    corecore