SearcharxivSearch

arXiv subjects

Rodrigo E. Menchón

Publications and source records attributed to Rodrigo E. Menchón.

3 recordsLinked to original sources

Algoritmos de Resolución de Problemas como disparadores de procesos de carácter compensatorio y de reconstrucción de saberes previos

In this work, we present a teaching strategy implemented in Introduction to Physics, corresponding to the first year of the Physics Teacher Degree at the National University of Rosario, whose main purpose is to provide students with tools to understand problem statements and exercises and to incorporate habits that favor their resolution and communication. For this purpose, we implemented the use of certain problemsolving algorithms, which we call Hopscotch-Algorithms, appealing to the image of this popular game in which steps can be skipped, rearranged or simultaneously executed. The aim is to stimulate a work method in a critical and problematized way, avoiding rigid or dogmatic applications of resolution steps. The testimonies collected indicate that the strategy was positively valued by the students.

physics.ed-ph

Tunable spin and transport in porphyrin-graphene nanoribbon hybrids

Recently, porphyrin units have been attached to graphene nanoribbons (Por-GNR) enabling a multitude of possible structures. Here we report first principles calculations of two prototypical, experimentally feasible, Por-GNR hybrids, one of which displays a small band gap relevant for its use as electrode in a device. Embedding a Fe atom in the porphyrin causes spin polarization with a spin ground state $S=1$. We employ density functional theory and nonequilibrium Green's function transport calculations to examine a 2-terminal setup involving one Fe-Por-GNR between two metal-free, small band gap, Por-GNR electrodes. The coupling between the Fe-$d$ and GNR band states results in a Fano anti-resonance feature in the spin transport close to the Fermi energy. This feature makes transport highly sensitive to the Fe spin state. We demonstrate how mechanical strain or chemical adsorption on the Fe give rise to a spin-crossover to $S=1$ and $S=0$, respectively, directly reflected in a change in transport. Our theoretical results provide a clue for the on-surface synthesis of Por-GNRs hybrids, which can open a new avenue for carbon-based spintronics and chemical sensing.

cond-mat.mes-hall