Electronic transport on molecular systems: an ab-initio approach

• Grant number: 11/11473-1
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: June 01, 2012
• End date: May 31, 2014
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Alexandre Reily Rocha
• Grantee: Jeconias Rocha Guimarães
• Host Institution: Instituto de Física Teórica (IFT). Universidade Estadual Paulista (UNESP). Campus de São Paulo. São Paulo , SP, Brazil

Abstract

Molecular electronic devices are the last frontier in terms of miniaturization, where a complete device can be build from just few atoms. Beyond the potential technological applications, interesting physical phenomena become dominant at the nanoscale. In that scope density functional theory (DFT) is a powerful tool to study the electronic structure of materials from first principles, and it is also the methodology with the best balance between computational cost and numerical accuracy. However, approximations necessary to apply of this theory lead to unsastifactory description of important phenomena (especially related to many-body effects), such as electronic correlations. The dynamic mean field theory (DMFT) is a modern and non-perturbative technique that provides the correct description of strong electron correlation effects and can be combined with DFT calculations. We propose in this project to implement a methodology that combines the formalism of DFT with the DMFT and the formalism of non-equilibrium Green's functions (NEGF) to calculate electronic transport in molecular systems. The combination of DFT + DMFT provides an accurate description of the electronic structure of systems with strong correlations, while the NEGF + DFT + DMFT method sallws for a computational analysis of electron correlation effects in electronic transport studies, such as the Kondo effect and Coulomb blockade.