Control and Local Measurement of the Spin Chemical Potential in a Magnetic Insulator

The spin chemical potential characterizes the tendency of spins to diffuse. Probing the spin chemical potential could provide insight into materials such as magnetic insulators and spin liquids and aid optimization of spintronic devices. Here, we introduce single-spin magnetometry as a generic platform for non-perturbative, nanoscale characterization of spin chemical potentials. We use this platform to investigate magnons in a magnetic insulator, surprisingly finding that the magnon chemical potential can be efficiently controlled by driving the system's ferromagnetic resonance. We introduce a symmetry-based two-fluid theory describing the underlying magnon processes, realize the first experimental determination of the local thermomagnonic torque, and illustrate the detection sensitivity using electrically controlled spin injection. Our results open the way for nanoscale control and imaging of spin transport in mesoscopic spin systems.Comment: 18 pages, 4 figure

Estudio comparativo y evaluaci?n del rendimiento de dos tecnolog?as de extracci?n de aceites esenciales de naranja, mandarina y tangelo

Existe una gran preocupaci?n por el empleo y desarrollo de nuevos procesos de extracci?n, los cuales minimicen los costos energ?ticos asociados a la operaci?n de extracci?n de aceites esenciales. As? mismo, se debe tomar en cuenta aspectos que actualmente son de suma importancia para la industria nacional y mundial, tales como la minimizaci?n de riesgos ambientales, el empleo de solventes m?s eficaces y f?cilmente recuperables y el aumento de la demanda de materias primas para la elaboraci?n de productos para consumo humano de alta calidad y con valor agregado. Es en este sentido que se pone atenci?n a t?cnicas tales como la destilaci?n por arrastre con vapor de agua. Integrado a esto, est?n los requerimientos de la industria alimenticia, farmac?utica y cosm?tica, entre otras. La presente investigaci?n es un estudio comparativo que eval?a el rendimiento entre la metodolog?a de extracci?n por arrastre a vapor cl?sica y la metodolog?a Clevenger, las cuales son tecnolog?as amigables con el ambiente, para la obtenci?n de aceites esenciales de naranja, mandarina y tangelo. Teniendo como objetivo principal la determinaci?n los par?metros adecuados para la extracci?n de aceites esenciales, a partir de la c?scara de los c?tricos mencionados. Para el desarrollo de esta investigaci?n se realiz? la revisi?n de literatura, 108 pruebas a escala de laboratorio y entrevistas a expertos. Los par?metros vinculados al volumen de aceite, tiempo de obtenci?n del mismo y rendimiento en la extracci?n son: el tama?o y la preparaci?n previa de las muestras de los c?tricos analizados. Analizando el rendimiento, el m?todo Cl?venger es superior que la metodolog?a cl?sica, los resultados obtenidos en el caso de la naranja son 6.08% y 0.24%, para la mandarina 1.31% y 0.41% y para el tangelo 3.11% y 0.31% respectivamente, los cuales se detallan m?s adelante

Spin dynamics in the optical cycle of single nitrogen-vacancy centres in diamond

We investigate spin-dependent decay and intersystem crossing in the optical cycle of single negatively-charged nitrogen-vacancy (NV) centres in diamond. We use spin control and pulsed optical excitation to extract both the spin-resolved lifetimes of the excited states and the degree of optically-induced spin polarization. By optically exciting the centre with a series of picosecond pulses, we determine the spin-flip probabilities per optical cycle, as well as the spin-dependent probability for intersystem crossing. This information, together with the indepedently measured decay rate of singlet population provides a full description of spin dynamics in the optical cycle of NV centres. The temperature dependence of the singlet population decay rate provides information on the number of singlet states involved in the optical cycle.Comment: 11 pages, 5 figure

Plan de negocio para la implementaci?n de una empresa de servicios integrales basada en tecnolog?a UAV (drones) en fertilizaci?n y fumigaci?n de cultivos espec?ficos

El presente plan de negocios consiste en una empresa de servicios integrales basada en tecnolog?a UAV (Drones) en fertilizaci?n y fumigaci?n de paltos y c?tricos en Lima e Ica, para empresas exportadoras del sector agr?cola dedicadas a las paltas y c?tricos, aprovechando el potencial de uso de estas nuevas tecnolog?as. Se necesitan 366,161.38 soles, entre drones (226,219.7 soles), otros activos fijos y gastos operativos y marketing, para la fase preoperativa. El proyecto ser? llevado a cabo por una empresa nueva con capitales propios. En el primer a?o se llegar? al punto de equilibrio.Finalmente, despu?s del estudio se confirm? que este negocio es viable, como resultado de la evaluaci?n financiera tenemos una VAN de 341,108 soles y una TIR de 46.23%

Engineered arrays of NV color centers in diamond based on implantation of CN- molecules through nanoapertures

We report a versatile method to engineer arrays of nitrogen-vacancy (NV) color centers in dia- mond at the nanoscale. The defects were produced in parallel by ion implantation through 80 nm diameter apertures patterned using electron beam lithography in a PMMA layer deposited on a diamond surface. The implantation was performed with CN- molecules which increased the NV defect formation yield. This method could enable the realization of a solid-state coupled-spin array and could be used for positioning an optically active NV center on a photonic microstructure.Comment: 12 pages, 3 figure

The Universal One-Loop Effective Action

We present the universal one-loop effective action for all operators of dimension up to six obtained by integrating out massive, non-degenerate multiplets. Our general expression may be applied to loops of heavy fermions or bosons, and has been checked against partial results available in the literature. The broad applicability of this approach simplifies one-loop matching from an ultraviolet model to a lower-energy effective field theory (EFT), a procedure which is now reduced to the evaluation of a combination of matrices in our universal expression, without any loop integrals to evaluate. We illustrate the relationship of our results to the Standard Model (SM) EFT, using as an example the supersymmetric stop and sbottom squark Lagrangian and extracting from our universal expression the Wilson coefficients of dimension-six operators composed of SM fields.Comment: 30 pages, v2 contains additional comments and corrects typos, version accepted for publication in JHE

Disembodied Mind: Cortical Changes Following Brainstem Injury in Patients with Locked-in Syndrome

Locked-in syndrome (LIS) following ventral brainstem damage is the most severe form of motor disability. Patients are completely entrapped in an unresponsive body despite consciousness is preserved. Although the main feature of LIS is this extreme motor impairment, minor non-motor dysfunctions such as motor imagery defects and impaired emotional recognition have been reported suggesting an alteration of embodied cognition, defined as the effects that the body and its performances may have on cognitive domains. We investigated the presence of structural cortical changes in LIS, which may account for the reported cognitive dysfunctions. For this aim, magnetic resonance imaging scans were acquired in 11 patients with LIS (6 males and 5 females; mean age: 52.3\ub15.2SD years; mean time interval from injury to evaluation: 9\ub11.2SD months) and 44 healthy control subjects matching patients for age, sex and education. Freesurfer software was used to process data and to estimate cortical volumes in LIS patients as compared to healthy subjects. Results showed a selective cortical volume loss in patients involving the superior frontal gyrus, the pars opercularis and the insular cortex in the left hemisphere, and the superior and medium frontal gyrus, the pars opercularis, the insular cortex, and the superior parietal lobule in the right hemisphere. As these structures are typically associated with the mirror neuron system, which represents the neural substrate for embodied simulation processes, our results provide neuroanatomical support for potential disembodiment in LIS