arXiv subjects

David Ley Dominguez

Publications and source records attributed to David Ley Dominguez.

4 recordsLinked to original sources

arXiv2024

Efecto Hall de espin inverso en peliculas de Nb Mo y Bi por bombeo de espin

The inverse spin Hall effect used for detection of spin currents was observed by voltage measurements in bilayers of normal metal (NM)/ferromagnetic metal (FM), using Nb, Mo and Bi as normal metal and Permalloy (Py, Ni$_{81}$Fe$_{19}$) as ferromagnetic metal. The spin current was generated by the spin pumping effect with ferromagnetic resonance. The samples were deposited by dc magnetron sputtering at room temperature on Si (001) substrates. The three bilayers of Nb/Py, Mo/Py and Bi/Py had a spin-orbit coupling large enough to observe the voltage generation by spin Hall effect

cond-mat.mes-hall↗

arXiv2022

Topological Frenkel Exciton-Polaritons in One-Dimensional Lattices of Strongly Coupled Cavities

Frenkel polaritons, hybrid light-matter quasiparticles, offer promises for the designing of new opto-electronic devices. However, their technological implementations are hindered by sensitivity to imperfections. Topology has raised as a way to circumvent defects and fabrication limitations. Here, we propose a lattice of cavities to realize the one-dimensional Su-Schrieffer-Heeger model (SSH) for topological Frenkel polaritons. By engineering the configuration of the cavities we demonstrate that the SSH topological and trivial phases can be accessed, which we unravel by complementary classical and quantum theories. We demonstrate the polariton edge state robustness under defects and the broadening of the photon and exciton lines. Our findings propose a realistic yet simple experimental setup to realize topological room temperature polaritons.

cond-mat.mes-hall↗

arXiv2022

The Fate of the Upper Polariton: Breakdown of the Quasiparticle Picture in the Continuum

Organic polaritons resulting from the strong hybridisation between photons and matter excitations have arisen as a suitable platform to device light-matter technological interfaces at room temperature. Despite their inherent complexity, organic polaritons are commonly regarded as coherent light-matter excitations that can be described in terms of Landau's quasiparticle approach. Here, we experimentally unveil the role of incoherent matter excitations on the polaritons by exploring the relevant energy-momentum parameter space. We demonstrate the emergence of a well-defined lower polariton branch and an intriguing fading of the upper polariton at its entrance to a continuum of matter excitations. This marks the breakdown of the simplistic quasiparticle picture for this branch and the formation of a more complex quantum state. Our experimental results are sustained by a general theoretical framework that allows understanding the light-matter hybridisation beyond the quasiparticle approach. Our work expands the understanding of organic polaritons in all their complexity and increases their technological significance.

cond-mat.mes-hall↗

arXiv2021

Fabricacion de un magnetron sputtering para deposito de peliculas nanometricas magneticas

This paper presents the development of scientific instrumentation for the fabrication of ferromagnetic thin films, by sputtering technique, for the use of 2-inch-diameter targets. Thin films were deposited using Permalloy alloy (Ni80Fe20) as ferromagnetic material at room temperature on Si (001) substrates. The film thicknesses were measured with profilometry and a deposition rate for this alloy of 16.2 nm/min was calculated. Scanning electron microscopy showed a continuous film formation and a chemical composition similar to the target

physics.ins-det↗