Dresden 2014 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 101: Transport - Poster Session

TT 101.10: Poster

Donnerstag, 3. April 2014, 15:00–19:00, P2

Orbital dependent absorbing boundary conditions for nanoscale spin transport — •Sebastian Frank and David Jacob — MPI of Microstructure Physics, Weinberg 2, 06120 Halle/Saale, Germany

Atomic and molecular junctions containing magnetic atoms are an intriguing field of research that may give rise to the development of nanoscale spintronic devices [1]. This type of system is particularly challenging: it is infinite, but non-periodic in the transport direction. In order to model the effect of the leads, we implement a novel methodology making use of absorbing boundary conditions (ABC) [2,3] within the ab initio quantum transport method for nanoscale devices based on DFT [4]. Our method allows us to determine orbital dependent ABC. This is crucial for the correct description of transition metal leads which have s-, p- and d-orbital channels. The orbital-dependence is included via a non-empirical criterion. The two free parameters are chosen by comparision with exact results for infinite chains and prove to be universal, i.e. have to be chosen only once and can then be applied to all types of systems. We apply our method to transition metal nanocontacts and find smooth density of states and transmission functions in agreement with experimental data.
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