Search results for "spin [structure function]"

Supercurrent-induced charge-spin conversion in spin-split superconductors

2018

We study spin-polarized quasiparticle transport in a mesoscopic superconductor with a spin-splitting field in the presence of coflowing supercurrent. In such a system, the nonequilibrium state is characterized by charge, spin, energy, and spin-energy modes. Here we show that in the presence of both spin splitting and supercurrent, all these modes are mutually coupled. As a result, the supercurrent can convert charge imbalance, which in the presence of spin splitting decays on a relatively short scale, to a long-range spin accumulation decaying only via inelastic scattering. This effect enables coherent charge-spin conversion controllable by a magnetic flux, and it can be detected by studyin…

Diseño y síntesis de nuevos materiales conmutables basados en el fenómeno de transición de espín

2023

Esta Tesis Doctoral actúa como compendio de síntesis y caracterización de nuevos materiales, generalmente porosos, que presentan el fenómeno de transición de espín (en inglés Spin Crossover, SCO). El principal objetivo de la Tesis Doctoral ha consistido en el diseño de estos nuevos polímeros de coordinación que combinan de forma sincrónica el fenómeno SCO asociado a los centros metálicos de FeII con otras propiedades de interés, siendo la motivación última su futura aplicación en dispositivos espintrónicos. Más concretamente, los esfuerzos sintéticos se han dedicado a la obtención de polímeros de coordinación de tipo Hofmann 2D que presentan: propiedades anfitrión-huésped selectivas, fluore…

Nuevos materiales moleculares multifuncionales conmutables con transición de espín

2022

Este trabajo de Tesis Doctoral se centra en la síntesis y caracterización de nuevos materiales moleculares conmutables basados en FeII, los cuales presentan el fenómeno de transición de espín (spin crossover, SCO). El objetivo principal de esta tesis doctoral ha sido el diseño y estudio de nuevos materiales multifuncionales de FeII que combinan el comportamiento SCO con otra propiedad físico-química de interés. La estrecha interrelación entre el fenómeno SCO y dicha propiedad ha sido seguida y estudiada por estudios magnéticos, cristalográficos y calorimétricos, entre otros. El capítulo 1 de esta tesis describe los conceptos teóricos más importantes del fenómeno SCO, donde los centros SCO e…

Dynamical behavior of a XX central spin model through Bethe ansatz techniques

2009

Spin caloric transport from density-functional theory

2019

Spin caloric transport refers to the coupling of heat with spin transport. Its applications primarily concern the generation of spin currents and control of magnetisation by temperature gradients for information technology, known by the synonym spin caloritronics. Within the framework of ab initio theory, new tools are being developed to provide an additional understanding of these phenomena in realistic materials, accounting for the complexity of the electronic structure without adjustable parameters. Here, we review this progress, summarising the principles of the density-functional-based approaches in the field and presenting a number of application highlights. Our discussion includes th…

Spin Crossover and Long-Lived Excited States in a Reduced Molecular Ruby.

2020

Abstract The chromium(III) complex [CrIII(ddpd)2]3+ (molecular ruby; ddpd=N,N′‐dimethyl‐N,N′‐dipyridine‐2‐yl‐pyridine‐2,6‐diamine) is reduced to the genuine chromium(II) complex [CrII(ddpd)2]2+ with d4 electron configuration. This reduced molecular ruby represents one of the very few chromium(II) complexes showing spin crossover (SCO). The reversible SCO is gradual with T 1/2 around room temperature. The low‐spin and high‐spin chromium(II) isomers exhibit distinct spectroscopic and structural properties (UV/Vis/NIR, IR, EPR spectroscopies, single‐crystal XRD). Excitation of [CrII(ddpd)2]2+ with UV light at 20 and 290 K generates electronically excited states with microsecond lifetimes. This…

Photoluminescence and Electron Spin Resonance of Silicon Dioxide Crystal with Rutile Structure (Stishovite)

2018

This work was supported by ERANET MYND. Also, financial support provided by Scientific Research Project for Students and Young Researchers Nr. SJZ/2017/2 realized at the Institute of Solid State Physics, University of Latvia is greatly acknowledged. The authors express our gratitude to R.I. Mashkovtsev for help in ESR signal interpretation. The authors are appreciative to T.I. Dyuzheva, L.M. Lityagina, N.A. Bendeliani for stishovite single crystals and to K. Hubner and H.-J. Fitting for stishovite powder of Barringer Meteor Crater.

risultati dello studio pilota del progetto spin uti: un modello per la valutazione ed il monitoraggio dei programmi in sanità pubblica

2007

Finite-frequency spin susceptibility and spin pumping in superconductors with spin-orbit relaxation

2020

Static spin susceptibility of superconductors with spin-orbit relaxation has been calculated in the seminal work of A.A. Abrikosov and L.P. Gor'kov [Sov. Phys. JETP, {\bf 15}, 752 (1962)]. Surprisingly the generalization of this result to finite frequencies has not been done despite being quite important for the modern topic of superconducting spintronics. The present paper fills this gap by deriving the analytical expression for spin susceptibility. The time-dependent spin response is shown to be captured by the quasiclassical Eilenberger equation with collision integrals corresponding to the ordinary and spin-orbit scattering. Using the developed formalism we study the linear spin pumping…

Chirality selective spin interactions mediated by the moving superconducting condensate

2018

We show that superconducting correlations in the presence of nonzero condensate velocity can mediate the peculiar interaction between localized spins that breaks the global inversion symmetry of magnetic moments. The proposed interaction mechanism is capable of removing fundamental degeneracies between topologically distinct magnetic textures. For the generic system of three magnetic impurities in the current-carrying superconductor, we find the energy term proportional to spin chirality. In realistic superconductor/ferromagnetic/superconductor setups we reveal significant energy differences between various magnetic textures with opposite chiralities. We calculate Josephson energies of junc…