18 research outputs found

    The Rashba Hamiltonian and electron transport

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    The Rashba Hamiltonian describes the splitting of the conduction band as a result of spin-orbit coupling in the presence of an external field and is commonly used to model the electronic structure of confined narrow-gap semiconductors. Due to the mixing of spin states some care has to be exercised in the calculation of transport properties. We derive the velocity operator for the Rashba-split conduction band and demonstrate that the transmission of an interface between a ferromagnet and a Rashba-split semiconductor does not depend on the magnetization direction, in contrast with previous assertions in the literature.Comment: one tex file, two figures; paper to appear in this form in PRB (RC

    Noise-assisted preparation of entangled atoms

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    We discuss the generation of entangled states of two two-level atoms inside an optical cavity. The cavity mode is supposed to be coupled to a white noise with adjustable intensity. We describe how the entanglement between the atoms inside the cavity arise in such a situation. The entanglement is maximized for intermediate values of the noise intensity, while it is a monotonic function of the spontaneous rate. This resembles the phenomenon of stochastic resonance and sheds more light on the idea to exploit white noise in quantum information processing.Comment: 4 pages, 4 figure

    Positronium-atom collisions

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    New results are presented for Ps(1s) scattering by H(1s), He(11^1S) and Li(2s). Calculations have been performed in a coupled state framework, usually employing pseudostates, and allowing for excitation of both the Ps and the atom. In the Ps(1s)-H(1s) calculations the H^- formation channel has also been included using a highly accurate H^- wave function. Resonances resulting from unstable states in which the positron orbits H^- have been calculated and analysed. The new Ps(1s)-He(11^1S) calculations still fail to resolve existing discrepancies between theory and experiment at very low energies. The possible importance of the Ps^- formation channel in all three collision systems is discussed

    Differential mechanisms underlying the modulation of delayed-rectifier K+ channel in mouse neocortical neurons by nitric oxide

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    10.1152/jn.01185.2004Journal of Neurophysiology9542167-2178JONE

    Epitaxial LaAl O3 thin film on silicon: Structure and electronic properties

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    10.1063/1.2736277Applied Physics Letters9018-APPL

    Predictors of the incidence of all-cause mortality and deaths due to diabetes and renal diseases among patients newly prescribed antihypertensive agents: A cohort study

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    <b>Background</b> Randomized trials have shown that the major antihypertensive drug classes are similarly effective to reduce mortality, but whether these drug class difference exists in clinical practice has been scarcely explored. This study evaluated the association between antihypertensive drug class, all-cause mortality and deaths due to diabetes or renal disease in real-life clinical settings.<p></p> <b>Methods</b> A clinical database in Hong Kong included all patients who were prescribed their first-ever antihypertensive agents between 2001 and 2005 from the public healthcare sector. All patients were followed up for five years, and grouped according to the initial antihypertensive prescription. The associations between antihypertensive drug class, all-cause mortality or combined diabetes and renal mortality, respectively, were evaluated by Cox proportional hazard models.<p></p> <b>Results</b> From 218,047 eligible patients, 33,288 (15.3%) died within five years after their first-ever antihypertensive prescription and among which 1055 patients (0.48%) died of diabetes or renal disease. After adjusted for age, gender, socioeconomic status, service settings, district of residence, medication adherence, and the number of comorbidities, each drug class was similarly likely to be associated with mortality due to diabetes or renal disease [Adjusted Hazard Ratios (AHR) ranged from 0.92 to 1.73, p = 0.287–0.939] and all-cause mortality (AHR ranged from 0.83 to 1.02) except for beta-blockers (AHR = 0.815, 95% C.I. 0.68–0.87, p = 0.024) when ACEI was used as a reference group in propensity score-adjusted analysis.<p></p> <b>Conclusions</b> These findings provide real-life evidence reinforcing that any major antihypertensive drug class is suitable as a first-line agent for management of hypertension as recommended by international guidelines

    Predictors of the incidence of all-cause mortality and deaths due to diabetes and renal diseases among patients newly prescribed antihypertensive agents: a cohort study

    No full text
    <b>Background</b> Randomized trials have shown that the major antihypertensive drug classes are similarly effective to reduce mortality, but whether these drug class difference exists in clinical practice has been scarcely explored. This study evaluated the association between antihypertensive drug class, all-cause mortality and deaths due to diabetes or renal disease in real-life clinical settings.<p></p> <b>Methods</b> A clinical database in Hong Kong included all patients who were prescribed their first-ever antihypertensive agents between 2001 and 2005 from the public healthcare sector. All patients were followed up for five years, and grouped according to the initial antihypertensive prescription. The associations between antihypertensive drug class, all-cause mortality or combined diabetes and renal mortality, respectively, were evaluated by Cox proportional hazard models.<p></p> <b>Results</b> From 218,047 eligible patients, 33,288 (15.3%) died within five years after their first-ever antihypertensive prescription and among which 1055 patients (0.48%) died of diabetes or renal disease. After adjusted for age, gender, socioeconomic status, service settings, district of residence, medication adherence, and the number of comorbidities, each drug class was similarly likely to be associated with mortality due to diabetes or renal disease [Adjusted Hazard Ratios (AHR) ranged from 0.92 to 1.73, p = 0.287–0.939] and all-cause mortality (AHR ranged from 0.83 to 1.02) except for beta-blockers (AHR = 0.815, 95% C.I. 0.68–0.87, p = 0.024) when ACEI was used as a reference group in propensity score-adjusted analysis.<p></p> <b>Conclusions</b> These findings provide real-life evidence reinforcing that any major antihypertensive drug class is suitable as a first-line agent for management of hypertension as recommended by international guidelines

    Thermally robust TaTbxN metal gate electrode for n-MOSFETs applications

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    10.1109/LED.2004.841469IEEE Electron Device Letters26275-77EDLE
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