CHEMICAL PHYSICS OF COMPLEX MATERIALS
The research line on “Chemical Physics of Complex Materials” addresses the structural and electronic properties of complex nanostructured materials. Experimental and theoretical efforts are combined to understand the properties, formation, and dynamics of different molecules and nanostructures at surfaces.
Several research groups are included in this research line, with a high degree of complementarity.
THE RESEARCH GROUPS
“Gas/solid interfaces” group, devoted to understanding the different mechanisms that determine the reactivity of atoms and small molecules at surfaces. The group has a large and solid background in studying and modeling the interaction of radiation and fast ions with solids, surfaces and nanostructures. and research activity has been extended to the interaction of thermal and hyperthermal atoms and molecules with surfaces. The group performs state-of-the-art molecular dynamics simulations of different physical and chemical processes, such as dissociative adsorption, molecular adsorption, molecular reflection, diffusion of chemical species, etc.
“Souza’s research” group activity is focused on condensed-matter theory, using computational techniques to study the properties of materials from first principles. The group’s work often involves the development of new theoretical approaches and algorithms, and their application to problems of current interest, including methods to study insulators in finite electric field, as well as to construct localized Wannier orbitals for metals. Phenomena which arise from the interplay between the collective magnetic order in solids and the spin-orbit interaction inside the constituent atoms have been recently addressed as well.
MODELIZATION AND SIMULATION
The “Modelization and Simulation” group, devoted to theoretical study, using first-principles methods, the electronic and structural properties of complex materials, clean and decorated surfaces, and nanostructures. An important part of the research activity is devoted to the development of simulation tools. It is one of the groups involved in the development of the linear-scaling SIESTA code. Other research areas of the group include: First-principles simulations of elastic and inelastic transport in nanostructures; simulations of scanning tunneling microscopy images and tunneling spectroscopies; theory of the interaction of ions and fast particles with solids, surfaces and nanostructures; ultra-fast electron processes and electronic excitations.
“Nanophysics Laboratory”, devoted to the experimental characterization of surfaces, low-dimensional systems, and novel nanostructured materiales prepared using a surface science approach and studied using scanning tunnelling (STM), atomic force microscopy (AFM), several photoemission (XPS, ARPES, UPS) and absorption (NEXAFS) techniques, among others. The laboratory aims to provide the complete structural and electronic characterization of nanostructured systems with atomic resolution. Special attention is given to self-assembled nanostructures like stepped surfaces and supramolecular assemblies. It is also worth to mention activity on curved crystals that has given rise to the development of a spin-off company, namely “Bihurcrystal“.
SPECTROSCOPY AT THE ATOMIC SCALE
“Spectroscopy at the atomic scale” group, devoted to structural and spectroscopical investigations at the local scale, based on scanning tunneling techniques. Electronic, vibrational, and transport properties at surfaces are addressed. The group’s main tool for studying nanostructures at the atomic scale is low temperature scanning probe microscopy. Local properties of nanoscale objects and surfaces are thus probed in ultra-high vacuum and at temperatures down to 1K.
A combined AFM/STM instrument capable of scanning atomic forces and tunneling current simultaneously at 1 K.
A combined ARPES/STM system with a double prep-chamber, which permits separate and joint ARPES/STM experiments. The ARPES chamber is an ultra-high resolution (0.1 degree, 5 meV) system, able of measuring solid samples down to 20 K.
Two separate STM/X Ray Photoemission (XPS) and STM/Magneto Optic Kerr Effect (MOKE) chambers for surface chemistry and surface magnetism experiments, respectively.
Several computing clusters at CFM and other institutions (such as DIPC) under collaborative research. Several scientific codes for ab initio calculations (DFT based on plane waves and local orbitals, quantum chemistry, quantum Monte Carlo), as well as other computational and graphic packages.
Development of scientific software for ab initio calculations as well as for other methodologies, including packages freely distributed to the scientific community (e.g., the SIESTA code developed in collaboration with other institutions).