Boltzmann Equations for Spin and Charge Relaxations in Superconductors

In a superconductor coupled with a ferromagnetic metal, spin and charge imbalances can be induced by injecting spin-polarized electron current from the ferromagnetic metal. We theoretically study a nonequilibrium distribution of quasiparticles in the presence of spin and charge imbalances. We show that four distribution functions are needed to characterize such a nonequilibrium situation, and derive a set of linearized Boltzmann equations for them by extending the argument by Schmid and Sch\"{o}n based on the quasiclassical Green's function method. Using the Boltzmann equations, we analyze the spin imbalance in a thin superconducting wire weakly coupled with a ferromagnetic electrode. The spin imbalance induces a shift $\delta\mu$ ($- \delta \mu$) of the chemical potential for up-spin (down-spin) quasiparticles. We discuss how $\delta \mu$ is relaxed by spin-orbit impurity scattering.Comment: 16 pages, 2 figure

‘Teachers’ to ‘academics’: the implementation of a modernisation project at one UK post-92 university

Among the many external forces that have impacted upon institutions, league tables have been the dynamic to which universities across the world are now responding. Following the appointment of a new vice-chancellor at one post-92 UK university, a modernisation project was introduced aimed at maximising the institutions’ research standing. For the institutional actors, the university’s lecturers, this modernisation project demanded a change in their working practices from one which had focused on teaching related activities to a situation where an emphasis was to be placed upon research. This study examines how university teachers at this institution understood and responded to the modernisation project to acquire research skills and provides an insight into a path-breaking strategic plan that was enacted within an historically dependent setting. It muses on the dialectics of institutional path dependency and the path breaking effect of a modernisation project that was stimulated by new managerialism

Historia de un campamento del Horizonte Medio de Huarmey, Perú (PV35-4)

Se presenta el estudio de un campamento temporal del Horizonte Medio situado en el desierto costero peruano al norte del valle de Huarmey. Se ha excavado la parte central del mismo pues presentaba la mayor cantidad de basura y dos fogones. Se ha podido establecer a base de la cerámica encontrada, que el sitio corresponde al Horizonte Medio 3. Los artefactos hallados son muy pocos, lo que es lógico dada la corta ocupación del sitio. Sin embargo se ha podido estudiar los abundantes restos botánicos y animales así como los fecales de llama que estaban acumulados en el lugar. También se ha encontrado coprolitos humanos. De ambos se ha realizado el examen polínico. Además de los excrementos humanos se ha efectuado el análisis del contenido de plantas y animales así como el parasitológico.Cet article étudie un campement temporaire de l’Horizon Moyen situé dans le désert côtier péruvien au nord de la vallée de Huarmey. La partie centrale du site a été choisie pour les fouilles car elle offrait la plus grande quantité de déchets ainsi que deux foyers. Il a été établi que le site correspondait à l’Horizon Moyen 3 grâce à la céramique qui y fut trouvée. Peu d’outillage a été trouvé en raison de la courte occupation du site, mais les restes abondants d’animaux et botaniques ainsi que les restes fécaux de llamas et humains accumulés sur le site ont fourni de précieuses indications. Les résultats des examens polliniques des coprolithes ainsi que les analyses du contenu de plantes, animaux et parasytes présents dans les coprolithes humains sont présentés ici.This is a study of a Middle Horizon temporary campsite located in the peruvian north coastal desert of the Huarmey Valley. The excavation was undertaken in the central part of the site since it contained the largest quantity debris and evidence of two bonfires. Its age was established using pieces of ceramic found on the site. A few artifacts were founded, probably due to the brief occupancy of the site, but were able to study the abundant botanical and animal remains, as well as llama and human coprolites. We present the results of tests for pollen in both the llama and human coprolites, as well as of tests for plant, animal, and parasite content in the human fecal remains are presented here

T-REX: Bare electro-dynamic tape-tether technology experimetn on sounding rocket S520

The project to verify the performance of space tether technology was successfully demonstrated by the launch of the sounding rocket S520 the 25tu. The project is the space demonstration of science and engineering technologies of a bare tape electrodynamic tether (EDT) in the international campaign between Japan, USA, Europe and Australia. Method of "Inverse ORIGAMI (Tape tether folding)" was employed in order to deploy the bare tape EDT in a short period time of the suborbital flight. The deployment of tape tether was tested in a various experimental schemes on ground to show high reliability of tape tether deployment. The rocket was launched on the summer of 2010 and deployed a bare electro-dynamic tape tether with length 132.6 m, which is the world record of the length deployment of tape tether. The verification of tether technology has found a variety kind of science and technology results as the first in the humankind and will lead a large number of applications of space tether technologie

Kerr effect of two-medium layered systems

Detailed and practical expressions are given for the magneto-optical Kerr effect (MOKE) for various configurations of two media. One is a magneto-optic (MO) one, and the other is a nonmagnetic (NM) medium. For a system of two thick media with a single interface, with a first-order approximation in MOKE term Q, the Kerr function is determined by the product of a MOKE term Q and an optical term η. A second type of system includes a thin MO (or NM) layer deposited on a thick NM (or MO) substrate. For a MO/(NM-substrate) configuration, the Kerr function is related to the Kerr effects from the air/MO and MO/NM interfaces, and to the Faraday effects of the MO layer, as well as to interference effects. The enhancement factor can be expected to be large by proper choice of materials. For a NM/(MO-substrate) configuration, the total Kerr function is related to the Kerr effect from the NM/MO interface and can be enhanced by interference. The enhancement factor is expected to be less than one if the NM layer is strongly absorbing. Calculations of Kerr effects for examples of the PtMnSb/AuAl2 and Fe/Cu configurations are given. These indicate that the peaks shown in the onset region of the interband transitions of Cu can be attributed to a dramatic change of the refractive index in that region. The merits of a MO/(NM-metallic) structure have been evaluated, and indicate that a better Kerr enhancement effect can be achieved if the refractive index of the MO layer is larger than one and is much larger than that of the metallic material. A drawback to this configuration comes from the fact that a MO material with a large refractive index value usually is not expected to have a large intrinsic Kerr effect. Journal of Applied Physics is copyrighted by The American Institute of Physics