Romeo de Coss Gómez

Researcher
Applied physics Department

Affiliation: Theory and Modeling of materials
Cinvestav-Mérida, Yucatan, México.

romeo.decoss@cinvestav.mx

Affiliations: Dr. Romeo de Coss Gómez is a Researcher in the Applied Physics Department at Cinvestav-Mérida, where he conducts basic and applied research in materials physics and quantum computing. He is also a member of the National System of Researchers, with level 3 recognition.

Research: Dr. de Coss has conducted research stays in prestigious laboratories and research centers, such as: Los Alamos National Laboratory and the Naval Research Laboratory in the United States, the International Centre for Theoretical Physics in Italy, and the Karlsruhe Institute of Technology in Germany; among others. To date, Dr. de Coss has published around 80 scientific articles in prestigious international journals, which have generated more than 2,600 citations. In addition, he has contributed significantly to the training of young researchers, having directed more than 50 bachelor’s, master’s and doctoral theses.

Understanding the sp-impurity induced magnetism in graphene-based systems

Defect-induced magnetism in graphene has been predicted theoretically and observed experimentally. However, there are open questions about the origin of the magnetic behavior when impurities with sp electrons are considered. Thus, results of ab-initio calculations for the electronic structure and spin magnetic moments of adsorbed and substitutional impurities in graphene (monolayer and bilayer) are presented and analyzed in the light of simple models. We found that the spontaneous magnetization arises from an electronic instability by the presence of a narrow impurity band at the Fermi level. Interestingly, the emergence of spin polarization requires the impurity to introduce an extra electron to the graphene lattice and that the impurity-carbon hybridization is close to the sp3 geometry. These features reveal that the charge doping sign and the hybridization degree play a fundamental role in the origin of sp magnetism in doped graphene. The analisis of the magnetic moments distribution reveal the superitinerant nature of the magnetism in doped graphene. Finally, strain effects on the defect-induced magnetic moments in graphene are also dicussed.