Strong competition between ΘII\Theta_{II}-loop-current order and dd-wave charge order along the diagonal direction in a two-dimensional hot spot model

We study the fate of the so-called $\Theta_{II}$-loop-current order that breaks both time-reversal and parity symmetries in a two-dimensional hot spot model with antiferromagnetically mediated interactions, using Fermi surfaces relevant to the phenomenology of the cuprate superconductors. We start from a three-band Emery model describing the hopping of holes in the CuO$_{2}$ plane that includes two hopping parameters $t_{pp}$ and $t_{pd}$, local on-site Coulomb interactions $U_{d}$ and $U_{p}$ and nearest-neighbor $V_{pd}$ couplings between the fermions in the copper [Cu$(3d_{x^{2}-y^{2}})$] and oxygen [O$(2p_{x})$ and O$(2p_{y})$] orbitals. By focusing on the lowest-energy band, we proceed to decouple the local interaction $U_{d}$ of the Cu orbital in the spin channel using a Hubbard-Stratonovich transformation to arrive at the interacting part of the so-called spin-fermion model. We also decouple the nearest-neighbor interaction $V_{pd}$ to introduce the order parameter of the $\Theta_{II}$-loop-current order. In this way, we are able to construct a consistent mean-field theory that describes the strong competition between the composite order parameter made of a quadrupole-density-wave and $d$-wave pairing fluctuations proposed in Efetov \emph{et al.} [Nat. Phys. \textbf{9}, 442 (2013)] with the $\Theta_{II}$-loop-current order parameter that is argued to be relevant for explaining important aspects of the physics of the pseudogap phase displayed in the underdoped cuprates.Comment: 16 pages, 5 figures. v2: minor revisions, references added. The magnetic moment per unit-cell associated with the $\Theta_{II}$-loop-current-phase is calculated and compared with experimental results. Accepted for publication in Physical Review

Electronic spectral function in fractionalized Pair Density Wave scenario

Studies of the electronic spectral function in cuprates by Angle-Resolved Photo-Emission Spectroscopy reveal unusual features in the pseudogap phase that persist in the superconducting phase. We address here these observations based on the recently proposed idea that the pseudogap is due to the fractionalization of modulated particle-particle pairs (a Pair Density Wave) into uniform particle-particle and modulated particle-hole pairs. The constraint that appears between these two types of pairs can be seen has an amplitude for the pseudogap energy scale. This constraint directly modify the electronic spectral function in the pseudogap phase. We derive a self-consistent equation for the pseudogap amplitude and show that it leads to the formation of Fermi arcs. The band dispersion obtained in the anti-nodal region is in good agreement with experimental ARPES observations in Pb$_{0.55}$Bi$_{1.5}$Sr$_{1.6}$La$_{0.4}$CuO$_{6+\delta}$ (Bi2201) and present a back-bending that goes to the Fermi level as we go away from the antinodal region. We also discuss the temperature dependence of the ARPES spectrum in the pseudogap and in the superconducting state

Sostenibilidad energética y viabilidad monetaria de los cultivos herbáceos extensivos ecológico en Andalucía

Una de las características más importantes de la agricultura es su capacidad para transformar la energía y generar “excedentes” energéticos con diversos usos (alimentación humana, animal, fertilización, etc.). Estos excedentes energéticos son potencialmente mayores en la agricultura ecológica como resultado del menor uso de insumos vinculados a la energía fósil. Los cereales y las leguminosas son cultivos que se caracterizan por altos outputs y balances de energía, ambos indicadores fundamentales de la sostenibilidad agraria. En este trabajo se analiza, tanto en términos monetarios como energéticos, el comportamiento de los cultivos extensivos ecológicos en Andalucía para el año 2005. Así mismo, se realiza un análisis comparativo entre los resultados energéticos obtenidos en el presente estudio y los aportados en otros estudios nacionales e internacionales. El balance monetario y energético de los cultivos extensivos se estimó en 2,47 y 3,65 respectivamente. Este último se incrementa hasta 6,49 si solamente se tiene en cuenta el uso de energía no renovable. En términos comparativos con cultivos convencionales, los resultados muestran un elevado grado de eficiencia energética

Energy sustainability and economic viability of organic extensive herbaceous crops in Andalusia

Una de las características más importantes de la agricultura es su capacidad para transformar la energía y generar “excedentes” energéticos con diversos usos (alimentación humana, animal, fertilización, etc.). Estos excedentes energéticos son potencialmente mayores en la agricultura ecológica como resultado del menor uso de insumos vinculados a la energía fósil. Los cereales y las leguminosas son cultivos que se caracterizan por altos outputs y balances de energía, ambos indicadores fundamentales de la sostenibilidad agraria. En este trabajo se analiza, tanto en términos monetarios como energéticos, el comportamiento de los cultivos extensivos ecológicos en Andalucía para el año 2005. Así mismo, se realiza un análisis comparativo entre los resultados energéticos obtenidos en el presente estudio y los aportados en otros estudios nacionales e internacionales. El balance monetario y energético de los cultivos extensivos se estimó en 2,47 y 3,65 respectivamente. Este último se incrementa hasta 6,49 si solamente se tiene en cuenta el uso de energía no renovable. En términos comparativos con cultivos convencionales, los resultados muestran un elevado grado de eficiencia energética.One of the most important characteristics of agriculture is its capacity to transform energy and generate energy “surpluses” with various uses (human food, animal feed, fertilization, etc.). These energy surpluses are potentially larger in ecological agriculture as result of low fossil fuel inputs related. Cereals and legumes are crops with high energy balance and output, both key agrarian sustainability indicators. This work analyses the behaviour of ecological extensive crops in Andalusia (2005), in both monetary and energy terms. In addition, a comparative analysis is made of the energy results obtained in the present study and those contributed by other national and international studies. The monetary and energy balance of extensive crops is estimated at 2.47 and 3.65, respectively. When only the use of non-renewable energy is taken into consideration, the energy balance increases and reaches 6.49. In comparative terms, the results show a high degree of energy efficiency

Generation of pure superconducting spin current in magnetic heterostructures via nonlocally induced magnetism due to Landau Fermi liquid effects

We propose a mechanism for the generation of pure superconducting spin-current carried by equal-spin triplet Cooper pairs in a superconductor (S) sandwiched between a ferromagnet (F) and a normal metal (N$_{\rm so}$) with intrinsic spin-orbit coupling. We show that in the presence of Landau Fermi-liquid interactions the superconducting proximity effect can induce non-locally a ferromagnetic exchange field in the normal layer, which disappears above the superconducting transition temperature of the structure. The internal Landau Fermi-liquid exchange field leads to the onset of a spin supercurrent associated with the generation of long-range spin-triplet superconducting correlations in the trilayer. We demonstrate that the magnitude of the spin supercurrent as well as the induced magnetic order in the N$_{\rm so}$ layer depends critically on the superconducting proximity effect between the S layer and the F and N$_{\rm so}$ layers and the magnitude of the relevant Landau Fermi-liquid interaction parameter. We investigate the effect of spin flip processes on this mechanism. Our results demonstrate the crucial role of Landau Fermi-liquid interaction in combination with spin-orbit coupling for the creation of spin supercurrent in superconducting spintronics, and give a possible explanation of a recent experiment utilizing spin-pumping via ferromagnetic resonance [Jeon $\it{ et}$ $\it{al.}$, Nat. Mat. ${\bf 17}$, 499 (2018)]

Economía Ecológica y Ecología Política en el Ámbito de la Educación Ambiental

La crisis social y ambiental es uno de los mayores problemas al que se enfrentan las sociedades a día de hoy. Uno de los retos más importantes de la educación es dotar al profesorado y al alumnado de las herramientas conceptuales adecuadas para comprender y analizar la situación actual desde una perspectiva compleja. La economía ecológica y la ecología política forman parte de ese nuevo paradigma en construcción: el de la complejidad. A su vez, los indicadores biofísicos utilizados en economía ecológica pueden constituir buenas herramientas pedagógicas, analíticas y discursivas dentro de la educación ambiental, sobre todo dentro del marco analítico que nos ofrece la ecología política

EL DERECHO HUMANO DE ASOCIACIÓN Y SU VULNERACIÓN POR LA SOCIEDAD POR ACCIONES SIMPLIFICADAS (SAS)

This study will establish the basics of Human Rights in general terms, thereafter will focus analyzing exclusively the human right called of Association included in the Mexican Constitution and international treaties that Mexico has ratified. Once the subject matter as to the Association Right has been settled, will review the relatively new type of company called “Simplified Stock Company” (SSC), introduced in our General Company Law since the amendment published in the Federal Official Gazette on March 14, 2016, within its analysis we will focus on its distinguishing characteristics, thereafter, will identify and provide legal basis on how the Human Right called Association would be infringed when applying some institutions included in the SSC, in our conclusion will provide the available control methods as to the safeguard of the association right.En el presente estudio pretendemos establecer las bases de los derechos humanos en general, para posteriormente avocarnos al análisis exclusivo del derecho humano denominado de Asociación contenido en la Constitución Política de los Estados Unidos Mexicanos y los tratados internacionales de que México forma parte. Una vez establecido el campo de aplicación del Derecho de Asociación, y sus restricciones, se procederá al estudio general de las sociedades mercantiles en México, para en forma seguida analizar el relativamente nuevo tipo social denominado “Sociedad por Acciones Simplificada” (SAS), que fue introducido en nuestra Ley General de Sociedades Mercantiles a partir de la reforma publicada en el Diario Oficial de la Federación el día 14 de marzo de 2016, dentro del estudio de esta figura jurídica, haremos énfasis en sus peculiares características, para posteriormente determinar y fundamentar que disposiciones de la SAS vulnerarían el Derecho Humano de Asociación, para finalizar estableciendo los medios de control que pueden ser utilizados para salvaguardar el derecho de asociación

Spin-orbit coupling suppression and singlet-state blocking of spin-triplet Cooper pairs

An inhomogeneous magnetic exchange field at a superconductor/ferromagnet interface converts spin-singlet Cooper pairs to a spin-aligned (i.e. spin-polarized) triplet state. Although the decay envelope of such triplet pairs within ferromagnetic materials is well studied, little is known about their decay in non-magnetic metals and superconductors, and in particular in the presence of spin-orbit coupling (SOC). Here we investigate devices in which triplet supercurrents are injected into the s-wave superconductor Nb. In the normal state of Nb, triplet supercurrents decay over a distance of 5 nm, which is an order of magnitude smaller than the decay of spin singlet pairs due to the SOC interacting with the spin associated with triplet pairs. In the superconducting state of Nb, triplet supercurrents are not able to couple with the singlet wavefunction and thus blocked by the absence of available equilibrium states in the singlet gap. The results offer new insight into the dynamics between s-wave singlet and s-wave triplet states.S.K., J.M.D-S., G.Y., X.M., L.F.C., H.K., M.G.B., and J.W.A.R. acknowledge funding from the EPSRC Programme Grant “Superspin” (no. EP/N017242/1) and EPSRC International Network Grant “Oxide Superspin” (no. EP/P026311/1). K.O. acknowledges the JSPS Programme “Fostering Globally Talented Researchers” (JPMXS05R2900005). S.M. and A.I.B. acknowledge funding from Russian Science Foundation (grant no. 20-12-00053, in part related to the theoretical calculations). Zh.D. and S.M. acknowledge financial support from the Foundation for the advancement of theoretical physics “BASIS.” S.M. acknowledges financial support from the Russian Presidential Scholarship (SP-3938.2018.5

Atrial Fibrillation Originating in the Inferior Vena Cava

Recurrence of atrial fibrillation (AF) despite successful isolation of the pulmonary veins (PVs) represents a great challenge. We present a patient with recurrent episodes of paroxysmal AF despite PV isolation in which a non-PV trigger was identified in the inferior vena cava. (Level of Difficulty: Intermediate.