Spin-polarized transport in a lateral two-dimensional diluted magnetic semiconductor electron gas

The transport property of a lateral two-dimensional diluted magnetic semiconductor electron gas under a spatially periodic magnetic field is investigated theoretically. We find that the electron Fermi velocity along the modulation direction is highly spin-dependent even if the spin polarization of the carrier population is negligibly small. It turns out that this spin-polarized Fermi velocity alone can lead to a strong spin polarization of the current, which is still robust against the energy broadening effect induced by the impurity scattering.Comment: 3 pages, 3 figures, submitted to Appl. Phys. Let

Magnetic coupling properties of rare-earth metals (Gd, Nd) doped ZnO: first-principles calculations

The electronic structure and magnetic coupling properties of rare-earth metals (Gd, Nd) doped ZnO have been investigated using first-principles methods. We show that the magnetic coupling between Gd or Nd ions in the nearest neighbor sites is ferromagnetic. The stability of the ferromagnetic coupling between Gd ions can be enhanced by appropriate electron doping into ZnO:Gd system and the room-temperature ferromagnetism can be achieved. However, for ZnO:Nd system, the ferromagnetism between Nd ions can be enhanced by appropriate holes doping into the sample. The room-temperature ferromagnetism can also be achieved in the \emph{n}-conducting ZnO:Nd sample. Our calculated results are in good agreement with the conclusions of the recent experiments. The effect of native defects (V$_{\rm{Zn}}$, V$_{\rm{O}}$) on the ferromagnetism is also discussed.Comment: 5 pages, 5 figure

Superconductivity in iron telluride thin films under tensile stress

By realizing in thin films a tensile stress state, superconductivity of 13 K was introduced into FeTe, an non-superconducting parent compound of the iron pnictides and chalcogenides, with transition temperature higher than that of its superconducting isostructural counterpart FeSe. For these tensile stressed films, the superconductivity is accompanied by the softening of the first-order magnetic and structural phase transition; and also, the in-plane extension and out-of-plane contraction are universal in all FeTe films independent of sign of lattice mismatch, either positive or negative. Moreover, the correlations were found exist between the transition temperatures and the tetrahedra bond angles in these thin films.Comment: 4 pages, 4 figures, accepted by Physical Review Letter

Unified covariant treatment of hyperfine splitting for heavy and light mesons

This paper aims at proving the fundamental role of a relativistic formulation for quarkonia models. We present a completely covariant description of a two-quark system interacting by the Cornell potential with a Breit term describing the hyperfine splitting. Using an appropriate procedure to calculate the Breit correction, we find heavy meson masses in excellent agreement with experimental data. Moreover, also when applied to light quarks and even taking average values of the running coupling constant, we prove that covariance properties and hyperfine splitting are sufficient to explain the light mesons spectrum and to give a very good agreement with the data.Comment: 4 page

Effect of NaHCO3 addition on the anaerobic co-digestion of fruit and vegetable waste and sewage sludge performance

Digestion of FVW residues with sewage sludge is feasible as long as the FVW to sludge ratio fed to the batch digester is not too large. The pH is the main variable determining the reactor performance and can be controlled by NaHCO3 addition.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Spin Hall effect in the kagome lattice with Rashba spin-orbit interaction

We study the spin Hall effect in the kagom\'{e} lattice with Rashba spin-orbit coupling. The conserved spin Hall conductance $\sigma_{xy}^{s}$ (see text) and its two components, i.e., the conventional term $\sigma_{xy}^{s0}$ and the spin-torque-dipole term $\sigma_{xy}^{s\tau}$, are numerically calculated, which show a series of plateaus as a function of the electron Fermi energy $\epsilon_{F}$. A consistent two-band analysis, as well as a Berry-phase interpretation, is also given. We show that these plateaus are a consequence of the various Fermi-surface topologies when tuning $\epsilon_{F}$. In particular, we predict that compared to the case with the Fermi surface encircling the $\mathbf{\Gamma}$ point in the Brillouin zone, the amplitude of the spin Hall conductance with the Fermi surface encircling the $\mathbf{K}$ points is twice enhanced, which makes it highly meaningful in the future to systematically carry out studies of the $\mathbf{K}$-valley spintronics.Comment: 7 pages, 3 figures. Phys. Rev. B (in press

Anaerobic co-digestion of pear residues and sewage sludge using a CSTR digester. Influence of the feed procedure

Anaerobic co-digestion of pear residues with sewage sludge is feasible. Important differences are obtained from the two feed regimes tested, with better results for the so-called continuous feed. The organic loading rate (OLR) is the important parameter for the methane productionUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Interplay between s-d exchange interaction and Rashba effect: spin-polarized transport

We investigate the spin-polarized transport properties of a two-dimensional electron gas in a n-type diluted magnetic narrow gap semiconductor quantum well subjected to a perpendicular magnetic and electric field. Interesting beating patterns in the magneto resistance are found which can be tuned significantly by varying the electric field. A resonant enhancement of spin-polarized current is found which is induced by the competition between the s-d exchange interaction and the Rashba effect [Y. A. Bychkov and E. I. Rashba, J. Phys. C 17, 6039 (1984)].Comment: 4 pages, 3 figures, Appl. Phys. Lett. (in press

Bringing out the gimp: fashioning the SM imaginary

The intention of this article is to investigate the cultural power associated with the gimp and the gimp mask. The gimp is a clothed or costumed SM body, frequently a submissive that often wears a leather or rubber costume that covers and effectuates the entire body including the face. The gimp is also a representation of SM that circulates throughout fashion and film and other forms of popular culture. Since the gimp’s first outing and naming in the film Pulp Fiction it has become the byword for the head-to-toe leather SM look that has been appropriated by a number of designers as way of exploring and exploiting the relationship between fashion, fetishism, and transgression. As a counterpoint to the popular image of SM in fashion and film, this article also explores how the artists Catherine Opie and Robert Mapplethorpe have represented the gimp, not as an index of horror or transgressive style rather as an affirmative image of their own SM communities that, while still intended to shock, is an defiant attempt to rescue or reclaim the gimp from its negative associations

Food production and consumption in Bamyan Province, Afghanistan: the challenges of sustainability and seasonality for dietary diversity

In Asia, high levels of malnutrition threaten the health and livelihoods of millions of households. This paper concentrates on linkages between agriculture and nutrition in Afghanistan where food and nutrition insecurity are increasing and agricultural sustainability is increasingly compromised by climate change. We explore seasonal patterns of food production and consumption in the remote and robust ecological environment of Shah Foladi, Bamyan Province. Analysis of qualitative data from household interviews in eight villages has provided a wealth of insights into the seasonality of diets. Even within a broadly homogeneous environment, households were found to be markedly heterogeneous in respect of their assets, production, market, finance and employment strategies. The so-called ‘lean season’ was found to vary accordingly. Nevertheless, a general lack of dietary diversity during much of the year is likely to cause micronutrient malnutrition, especially for the vulnerable groups of children, adolescent girls and women. Potential interventions are proposed which need to account for the local context in order to overcome the natural and political constraints. These strategies include agricultural innovation and multi-sectoral policy approaches. In the end, reducing national insecurity is a pre-requisite for sustainable improvement in nutrition-sensitive agricultural development