Examinando por Autor "Laroze, David"

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Breather Bound States in a Parametrically Driven Magnetic Wire
(MDPI, 2024-11-22) Castro, Camilo José; Ortega-Piwonka, Ignacio; Malomed, Boris A.; Urzagasti, Deterlino; Pedraja-Rejas, Liliana; Díaz, Pablo; Laroze, David
We report the results of a systematic investigation of localized dynamical states in the model of a one-dimensional magnetic wire, which is based on the Landau-Lifshitz-Gilbert (LLG) equation. The dissipative term in the LLG equation is compensated by the parametric drive imposed by the external AC magnetic field, which is uniformly applied perpendicular to the rectilinear wire. The existence and stability of the localized states is studied in the plane of the relevant control parameters, namely, the amplitude of the driving term and the detuning of its frequency from the parametric resonance. With the help of systematically performed simulations of the LLG equation, the existence and stability areas are identified in the parameter plane for several species of the localized states: stationary single- and two-soliton modes, single and double breathers, drifting double breathers with spontaneously broken inner symmetry, and multisoliton complexes. Multistability occurs in this system. The breathers emit radiation waves (which explains their drift caused by the spontaneous symmetry breaking, as it breaks the balance between the recoil from the waves emitted to left and right), while the multisoliton complexes exhibit cycles of periodic transitions between three-, five-, and seven-soliton configurations. Dynamical characteristics of the localized states are systematically calculated too. These include, in particular, the average velocity of the asymmetric drifting modes, and the largest Lyapunov exponent, whose negative and positive values imply that the intrinsic dynamics of the respective modes is regular or chaotic, respectively.
Scientific production in Latin American physics: a bibliometric analysis
(Springer, 2024-06-14) Pedraja-Rejas, Liliana; Garrido-Tamayo, Miguel Ángel; Ortega-Piwonka, Ignacio; Rodríguez-Ponce, Emilio; Laroze, David
In this article, a bibliometric analysis of the authors, journals, research institutions, coun- tries and keywords found in 27,750 documents from the Web of Science written by Latin American authors or co-authors in Physics between the years 2013 and 2022, is carried out. The results show that the last ten years have seen increasing numbers in the scientific production and that the more outstanding authors of the region are mainly from Brazil, Mexico, Argentina, Chile and Colombia, with the United States being the non-Latin Amer- ican country involved in the largest number of collaborations. Brazil is the most productive country in the region and the areas that draw most interest are Optics, Materials Science, Physics Applied, Nanotechnology and Chemistry Physical. Given that collaborations with the European Organization for Nuclear Research (CERN) involve more than 1000 authors per document or other large similar collaborations, works associated with high energy physics have been excluded from this study.