Regensburg 2013 – scientific programme

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MA: Fachverband Magnetismus

MA 22: Transport: Molecular Electronics (jointly with CPP, HL, and MA)

MA 22.12: Talk

Wednesday, March 13, 2013, 12:30–12:45, H2

Full ab initio description of strong electronic correlations in molecular devices — •David Jacob — Max-Planck-Institut für Mikrostrukturphysik, Halle

In order to obtain a full first-principles description of the correlated electronic structure and transport properties of nanoscopic devices we combine the so-called Coulomb-Hole-Screened-Exchange (COHSEX) approximation with more sophisticated many-body techniques such as the Dynamical Mean-Field Theory (DMFT). While the former yields an effective mean-field description of the weakly correlated conduction electrons, the latter describes the dynamic correlations of the strongly interacting electrons in the 3d- or 4f-shells of transition metal atoms. The combination of DMFT with COHSEX instead of Density Functional Theory (DFT) improves upon our recently developed "Molecular DMFT" approach [1,2] in two important aspects: First, the COHSEX yields the effective Coulomb interaction U for the strongly interacting electrons. Second, unlike in DFT+DMFT calculations the double-counting correction for COHSEX+DMFT is exactly known and straight-forward to calculate. With this approach it is now possible to actually predict e.g. the occurance of the Kondo effect in magnetic atoms and molecules on metal surfaces and attached to metallic leads, and to investigate the complex nature of the Kondo effect in these sytems.
[1] D. Jacob et al., PRL 103, 016803 (2009); PRB 82, 195115 (2010)
M. Karolak et al., PRL 107, 146604 (2011)