Search results for "14"

Coupling the Higgs mode and ferromagnetic resonance in spin-split superconductors with Rashba spin-orbit coupling

2022

We show that the Higgs mode of superconductors can couple with spin dynamics in the presence of a static spin-splitting field and Rashba spin-orbit coupling. The Higgs-spin coupling dramatically modifies the spin susceptibility near the superconducting critical temperature and consequently enhances the spin pumping effect in a ferromagnetic insulator/superconductor bilayer system. We show that this effect can be detected by measuring the magnon transmission rate and the magnon-induced voltage generated by the inverse spin Hall effect.

Superconducting Triplet Rim Currents in a Spin-Textured Ferromagnetic Disk

2022

Since the discovery of the long-range superconducting proximity effect, the interaction between spin-Triplet Cooper pairs and magnetic structures such as domain walls and vortices has been the subject of intense theoretical discussions, while the relevant experiments remain scarce. We have developed nanostructured Josephson junctions with highly controllable spin texture, based on a disk-shaped Nb/Co bilayer. Here, the vortex magnetization of Co and the Cooper pairs of Nb conspire to induce long-range triplet (LRT) superconductivity in the ferromagnet. Surprisingly, the LRT correlations emerge in highly localized (sub-80 nm) channels at the rim of the ferromagnet, despite its trivial band s…

Superfluid weight and Berezinskii-Kosterlitz-Thouless transition temperature of twisted bilayer graphene

2019

We study superconductivity of twisted bilayer graphene with local and non-local attractive interactions. We obtain the superfluid weight and Berezinskii-Kosterlitz-Thouless (BKT) transition temperature for microscopic tight-binding and low-energy continuum models. We predict qualitative differences between local and non-local interaction schemes which could be distinguished experimentally. In the flat band limit where the pair potential exceeds the band width we show that the superfluid weight and BKT temperature are determined by multiband processes and quantum geometry of the band.

Competition of electron-phonon mediated superconductivity and Stoner magnetism on a flat band

2018

The effective attractive interaction between electrons, mediated by electron-phonon coupling, is a well-established mechanism of conventional superconductivity. In metals exhibiting a Fermi surface, the critical temperature of superconductivity is exponentially smaller than the characteristic phonon energy. Therefore, such superconductors are found only at temperatures below a few kelvin. Systems with flat energy bands have been suggested to cure the problem and provide a route to room-temperature superconductivity, but previous studies are limited to only BCS models with an effective attractive interaction. Here we generalize Eliashberg's theory of strong-coupling superconductivity to syst…

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…

Normal-Metal–Insulator–Superconductor Tunnel Junction With Atomic-Layer-Deposited Titanium Nitride as Superconductor

2015

Re-Inhabiting Inner Areas Triggering New Regeneration Trajectories: The Case Study of Sicani in Sicily

2022

The Italian debate on the so-called ‘inner areas’ has received a much-needed boost, following the COVID-19 pandemic, which has further highlighted the differences between metropolitan and inner areas. While the progressive depopulation of inner areas is a worrying phenomenon, the limits of incessant urbanisation and the concentration of settlement and infrastructure policies in large conurbations have become evident. Departing from the framework of the B4R-Branding4Resilience research project of national interest and, by continuing in the furrow initiated by the SNAI, but also surpassing it, the aim of the University of Palermo’s research is to define the requirement for a…

Towards Controlled Synthesis of Water-Soluble Gold Nanoclusters : Synthesis and Analysis

2019

Water-soluble gold nanoclusters with well-defined molecular structures and stability possess particular biophysical properties making them excellent candidates for biological applications as well as for fundamental spectroscopic studies. The currently existing synthetic protocols for atomically monodisperse thiolate-protected gold nanoclusters (AuMPCs) have been widely expanded with organothiolates, yet the direct synthesis reports for water-soluble AuMPCs are still deficient. Here, we demonstrate a wet-chemistry pH-controlled synthesis of two large water-soluble nanoclusters utilizing p-mercaptobenzoic acid (pMBA), affording different sizes of plasmonic AuMPCs on the preparative scale (∼7 …

CERN IRRADIATION FACILITIES.

2017

CERN provides unique irradiation facilities for applications in dosimetry, metrology, intercomparison of radiation protection devices, benchmark of Monte Carlo codes and radiation damage studies to electronics.

Genetic Factors as Promising Biomarkers of Sporadic Ascending Aortic Aneurysm

2014

Thoracic aorta shows various changes with advancing age and a progressive deterioration in structure and function. As a result, vascular remodeling (VR) and medial degeneration (MD) occur. VR and MD are typical entities of sporadic thoracic aortic aneurysm (TAA), actually considered a common and serious health risk and a pathology by unclear mechanisms. Increased activity of the coagulation system, inflammation, activation of extracellular matrix remodeling and endothelial dysfunction pathways have been recently evidenced to have a key role in its onset. Thus, polymorphisms of the coagulation system [fibrinogen (rs1800790); Factor II ( rs1799963); Factor V (rs6025); Factor VII (rs121964926)…