title: Dynamical vertex approximation for nanoscopic systems.
abstract: With an increasing complexity of nanoscopic systems and the modeling thereof, new theoretical tools are needed for a reliable calculation of complex systems with strong electronic correlations. To this end, we propose a new approach based on the recently introduced dynamical vertex approximation. We demonstrate its reliability already on the one-particle vertex (i.e., dynamical mean field theory) level by comparison with the exact solution. Modeling a quantum point contact with 110 atoms, we show that the contact becomes insulating already before entering the tunneling regime due to a local Mott-Hubbard transition occurring on the atoms which form the point contact.
authors.affiliation: Institute of Solid State Physics, Vienna University of Technology, 1040 Vienna, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Valli
authors.forename: G
authors.initials: G
authors.lastname: Sangiovanni
authors.forename: O
authors.initials: O
authors.lastname: Gunnarsson
authors.forename: A
authors.initials: A
authors.lastname: Toschi
authors.forename: K
authors.initials: K
authors.lastname: Held