Berlin 2012 – scientific programme

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O: Fachverband Oberflächenphysik

O 20: Theoretical methods I

O 20.1: Talk

Monday, March 26, 2012, 17:45–18:00, A 060

Can we replace a metallic support for an ultra-thin insulating film using a perfect conductor model? — •Ivan Scivetti and Mats Persson — Surface Science Research Centre, the University of Liverpool, Liverpool L69 3BX, UK

The study of atoms and molecules deposited on ultra-thin, insulating films supported by metal substrates is an emerging and exciting area of research, in which Density Functional Theory (DFT) could play a key role. In fact, further understanding of these systems could lead to creation and design of novel functionalized nanostructures or molecular devices for electronics, photovoltaics, information storage and processing, catalysis and chemical sensors [1].

However, DFT simulations of these systems are very challenging, since charging plays in many cases an important role [2]. Therefore, there is a need to develop simplified computational schemes.

In this work we assume that the metallic support can be replaced by a perfect conductor model without having to consider the metal electrons explicitly, which would enable us to handle different charge states and reduce the computational time. To this end, we have developed a novel DFT approach, providing appropriate expressions for the total energy and forces. To evaluate the quality and the range of this approximation, we show preliminary results for adsorbates over an insulating film in different charge states.

[1] Mohn, F et. al., Phys. Rev. Letter 105, 266102 (2010).

[2] Jascha Repp, et al., Science 305, 493 (2004).