Berlin 2008 – wissenschaftliches Programm

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SYNF: Symposium Ferroic materials and novel functionalities

SYNF 2: Ferroic materials and novel functionalities II

SYNF 2.2: Hauptvortrag

Dienstag, 26. Februar 2008, 15:00–15:30, A 151

New physics from electron correlations at oxide interfaces — •Warren E. Pickett¹ and Rossitza Pentcheva² — ¹Department of Physics, University of California, Davis, California 95616, USA — ²Department of Earth and Environmental Sciences, University of Munich, Theresienstrasse 41, 80333 Munich, Germany

Disruption of periodic order in ionic materials (simplest examples are flat surfaces and abrupt heterointerfaces) often entail "charge mismatch" and polar layers. The strength of Coulomb forces dictates that the mismatch be accommodated within a few atomic distances. A mechanism in which the mismatch can be neutralized within a single atomic layer -- strong intra-atomic repulsion resulting in charge order -- will be discussed, with examples taken from ab initio calculations of abrutp LAO/STO and LTO/STO (001) heterointerfaces. The properties (conductivity, magnetism) of the interface can be dependent on atomic relaxation and of defects (oxygen vacancies, cation exchange, etc.). The "new materials " aspects of short-period multilayers will also be discussed.