The Expanded mtDNA Phylogeny of the Franco-Cantabrian Region Upholds the Pre-Neolithic Genetic Substrate of Basques

9 p.

Spin-helical Dirac states in graphene induced by polar-substrate surfaces with giant spin-orbit interaction: a new platform for spintronics

Spintronics, or spin electronics, is aimed at efficient control and manipulation of spin degrees of freedom in electron systems. To comply with demands of nowaday spintronics, the studies of electron systems hosting giant spin-orbit-split electron states have become one of the most important problems providing us with a basis for desirable spintronics devices. In construction of such devices, it is also tempting to involve graphene, which has attracted great attention because of its unique and remarkable electronic properties and was recognized as a viable replacement for silicon in electronics. In this case, a challenging goal is to lift spin degeneracy of graphene Dirac states. Here, we propose a novel pathway to achieve this goal by means of coupling of graphene and polar-substrate surface states with giant Rashba-type spin-splitting. We theoretically demonstrate it by constructing the graphene@BiTeCl system, which appears to possess spin-helical graphene Dirac states caused by the strong interaction of Dirac and Rashba electrons. We anticipate that our findings will stimulate rapid growth in theoretical and experimental investigations of graphene Dirac states with real spin-momentum locking, which can revolutionize the graphene spintronics and become a reliable base for prospective spintronics applications.

La crisi presente. La autonomía de la voluntad La operatividad de la clausula Rebus sic Stantibus

La situación que emergió a partir del año 2008, hizo resurgir la necesidad de indagar sobre la posibilidad jurídica y la necesidad social de revisar los pactos contractuales vigentes. Por tanto se pretendía deducir si la situación de crisis económica permitía excepciones al principio de la autonomía de la voluntad, y llegados a este punto determinar si era posible la aplicación de la clausula rebus sic stantibus, es decir, si era posible modificar el contenido contractual inicialmente querido y pactado por las partes. Esta tarea se vio incentivada por varios pronunciamientos del Tribunal Supremo, que en términos generales consideraron la clausula como aplicación normalizada, dejando atrás la concepción de regla peligrosa para el sistema contractual.