Dresden 2014 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

O: Fachverband Oberflächenphysik

O 38: Invited Talk (Stefan Heinze)

O 38.1: Invited Talk

Wednesday, April 2, 2014, 09:30–10:15, TRE Phy

Understanding STM experiments on single-atom junctions from first-principles — •Stefan Heinze — Institut für Theoretische Physik und Astrophysik, Christian-Albrechts-Universtität zu Kiel, Germany

Today, scanning tunneling microscopy (STM) allows to create artificial nanostructures at surfaces atom-by-atom and to locally probe their structural, electronic, magnetic, and transport properties at the atomic level. In order to understand such experiments it is often indispensable to use a first-principles approach based on density functional theory. It is particularly intriguing to explore physical properties at the single atom limit. Here, I will show that it is possible to image the spin direction of single magnetic atoms on surfaces [1] and how the spin-valve effect in single-atom junctions can be explained [2]. We found that in such experiments the interaction between tip and adsorbed atom can become essential [3]. Surprisingly, it is also feasible to detect the spin-quantization axis of single atoms using non-magnetic STM tips [4] due to spin-orbit coupling. This effect – the so-called tunneling anisotropic magnetoresistance – can be implemented into a simple model of STM which allows fast simulation of spin-polarized and non-spin-polarized STM images [5].

[1] D. Serrate et al., Nature Nanotech. 5, 350 (2010).

[2] M. Ziegler et al., New J. of Phys. 13, 085011 (2011).

[3] C. Lazo et al., Phys. Rev. B 86, 180406 (R) (2012).

[4] N. Néel et al., Phys. Rev. Lett. 110, 037202 (2013).

[5] K. von Bergmann et al., Phys. Rev. B 86, 134422 (2012).